Schematic Volt: converter

Showing posts with label converter. Show all posts

Showing posts with label converter. Show all posts

Wednesday, November 19, 2014

3V to 40 Volt DC Converter Circuit

Switching regulator subsystems intended for use asdc to dc converters. 3V to 40 Volt DC Converter circuit | The use of switching regulators is becoming more pronounced over that of linear regulators because the size reductions in new equipment designs require greater conversion efficiency. Another major advantage of the switching regulator is that it has increasednapplication flexibility of output voltage. The output can be less than, greater than, or of opposite polarity to that of the input voltage.

The MC34063 series is a monolithic control circuit containing all the active functions required for dc to dcconverters. This device contains an internal temperature compensated reference, comparator, controlled duty cycle oscillator with an active peak current limit circuit, driver, and a high current output switch. This series was specifically designed to be incorporated in step–up, step–down and voltage–inverting converter applications. These functions are contained in an 8–pin dual in–line package.

FEATURES 3V to 40 Volt DC Converter :
· Wide Input Voltage Range 3 V to 40 V
· Precision Internal Reference 2%
· High Output Switch Current Up to 1.5 A
· Short-Circuit Current Limiting
· Adjustable Output Voltage
· Low Standby Current
· Oscillator Frequency Up to 100 kHz

Sunday, November 16, 2014

Battery backup converter with one NiCd cell

Battery-backup

Battery-backup converter with one NiCd cell

Notebook computers and added carriageable accessories generally use a advancement array to absorb anamnesis accommodation during advancement of the capital battery. Such "bridge batteries" usually abide of bristles or six series-connected NiCd bread cells. Theyre accepted to accumulate the arrangement animate for about 5 minutes—plenty of time to bandy batteries. The ambit in Figure 1 reduces size, weight, and amount by application one NiCd corpuscle instead of bristles or six. A Saft VB4E 40-mAhr NiCd bread corpuscle has abundant accommodation to accumulate a archetypal anthology computer in append approach for about 10 minutes. All apparatus (excluding the bread cell) absorb beneath than 1/2 in.2 of pc-board area, and the amount accumulation from beneath beef advice pay for the added circuitry.

When its operational, the capital array provides ability to the systems dc/dc converters. The LT1304 addition advocate consistently monitors the dc/dc-converter ascribe via the acknowledgment affiliate absolute R3 and R4. Once the FB pin drops beneath 1.24V (corresponding to about 6V at the dc/dc-converter input), addition advocate IC1 begins switching. Accepted comes from B1, through L1, and into the SW pin on IC1. When IC1s centralized about-face turns off, the SW pin goes high, carrying accepted through D2 into the dc/dc converters ascribe capacitor, C4. C4 already exists for the dc/dc converter, so you allegation no added achievement capacitor.

The LT1304 switches at about 200 kHz; thus, L1 can be small. Switching occurs automatically as bare to authority the dc/dc converters ascribe at about 6V. Ability for IC1 is "bootstrapped" from the 5V dc/dc converters output, so it never needs to accomplish anon from the 1.2V NiCd bread cell. Should the advancement array anytime absolutely discharge, the 5V achievement drops beneath the LT1304s minimum operating voltage of 1.5V, and the absolute arrangement shuts down. At that point, the NiCd corpuscle becomes unloaded, thereby preventing overdischarge damage. Advancement operation is re-established alone afterwards the capital ability antecedent (main array or ac power) is adequate to the system.

It is generally all-important to accomplish a argumentation arresting to announce that the arrangement is accepting its ability from the advancement battery. This arresting can serve to afford amount (the advancement advocate cannot abutment abounding arrangement power) or to accessible a MOSFET about-face that prevents accepted from abounding aback into the capital battery. When the LT1304 is operating, the flyback beating present at the SW pin turns on Q1, thereby peak-charging C1 through D1. Once the voltage on pin 1 exceeds 1.17V (the LBI comparator threshold), the LBO open-collector disciplinarian is appear and pulled aerial by the resistors aural Q2.

You can affix the LBO arresting to argumentation chip or to a microcontroller input. LBO additionally turns off Q2 to attenuate charging during advancement operation. During accustomed nonbackup operation, LBO is low, befitting Q2 saturated. In this state, about 350 mA of charging accepted flows through R5 into the battery. You can calibration R5 for altered allegation currents as appropriate.

Wednesday, November 12, 2014

Valve Sound Converter

‘Valve sound’ is not just an anachronism: there are those who remain ardent lovers of the quality of sound produced by a valve amplifier. However, not everyone is inclined to splash out on an expensive valve output stage or complete amplifier with a comparatively low power output. Also, for all their aesthetic qualities, modern valve amplifiers burn up (in the full sense of the word!) quite a few watts even at normal listening volume, and so are not exactly environmentally harmless. This valve sound converter offers a cunning way out of this dilemma. It is a low cost unit that can be easily slipped into the audio chain at a suitable point and it only consumes a modest amount of energy.

A valve sound converter can be constructed using a common-or-garden small-signal amplifier using a readily-available triode. Compared to using a pentode, this simplifies the circuit and, thanks to its less linear characteristic, offers even more valve sound. For stereo use a double triode is ideal. Because only a low gain is required, a type ECC82 (12AU7) is a better choice than alternatives such as the ECC81 (12AT7) or ECC83 (12AX7). This also makes things easier for home brewers only used to working with semiconductors, since we can avoid any difficulties with high voltages, obscure transformers and the like:the amplifier stage uses an anode voltage of only 60 V, which is generated using a small 24 V transformer and a voltage doubler (D3, D4, C4 and C5).

Since the double triode only draws about 2mA at this voltage, a 1 VA or 2 VA transformer will do the job. To avoid ripple on the power supply and hence the generation of hum in the converter, the anode voltage is regulated using Zener diodes D1 and D2, and T1. The same goes for the heater supply: rather than using AC, here we use a DC supply, regulated by IC1. The 9 V transformer needs to be rated at at least 3 VA. As you will see, the actual amplifier circuit is shown only once. Components C1 to C3, R1 to R4, and P1 need to be duplicated for the second channel.

The inset valve symbol in the circuit diagram and the base pinout diagram show how the anode, cathode and grid of the other half of the double triode (V1.B) are connected. Construction should not present any great difficulties. Pay particular attention to screening and cable routing, and to the placing of the transformers to minimise the hum induced by their magnetic fields. Adjust P1 to set the overall gain to 1 (0 dB). The output impedance of 47 kΩ is relatively high, but should be compatible with the inputs of most power amplifiers and preamplifiers.

For a good valve sound, the operating point of the circuit should be set so that the audio output voltage is in the region of a few hundred millivolts up to around 1.5 V. If the valve sound converter is inserted between a preamplifier and the power amplifier, it should be before the volume control potentiometer as otherwise the sound will change significantly depending on the volume. As an example, no modifications are needed to an existing power amplifier if the converter is inserted between the output of a CD player and the input to the amplifier.

Saturday, November 8, 2014

USB Converter

Does this sound familiar: you buy a small piece of equipment, such as a programming & debugging interface for a microcontroller, and you have to use a clunky AC wall adapter to supply it with power? It’s even worse when you’re travelling and there’s no mains socket anywhere in sight. Of course, you can use the USB bus directly as a power source if the supply voltage is 5 V. If you need a higher voltage, you can use the USB converter described here. This small switch-mode step-up converter can generate an output voltage of up to 15 V with a maximum output current of 150 mA.

The LM3578 is a general-purpose switchmode voltage converter. Figure 1 shows its internal block diagram. Here we use it as a step-up converter. The circuit diagram in Figure 2 shows the necessary components. Voltage conversion is achieved by switching on the internal transistor until it is switched off by the comparator or the current-limiting circuit. The collector current flows through coil L1, which stores energy in the form of a magnetic field. When the internal transistor is switched off, the current continues flowing through L1 to the load via diode D1. However, the voltage across the coil reverses when this happens, so it is added to the input voltage. The resulting output voltage thus consists of the sum of the input voltage and the induced voltage across the coil.

The output voltage depends on the load current and the duty cycle of the internal transistor. Voltage divider R5/R6 feeds back a portion of the output voltage to the comparator in the IC in order to regulate the output voltage. C5 determines the clock frequency, which is approximately 55 kHz. Network R4, C2 and C3 provides loop compensation. The current-sense resistor for the current-limiting circuit is formed by three 1-Ω resistors in parallel (R1, R2 and R3), since SMD resistors with values less than 1 Ω are hard to find. The output voltage ripple is determined by the values and internal resistances of capacitors C11, C8, C7 and C6.

The total effective resistance is reduced by using several capacitors, and this also keeps the construction height of the board low. L2, C1, C9 and C10 act as an input filter. Ensure that the DC resistance of coil L2 is no more than 0.5 Ω. Use a Type B PCB-mount USB connector for connection to the USB bus. A terminal strip with a pitch of 5.08 mm can be used for the output voltage connector. Of course, you can also solder a cable directly to the board. Two additional holes are provided in the circuit board for this purpose. As we haven’t been able to invent a device that produces more energy than it consumes, you should bear in mind that the input current of the circuit is higher than the output current. As a general rule, you can assume that the input current is equal to the product of the output current and the output voltage divided by the input R5 and R6 for other output voltages:

6V:	R5 = 47k, R6 = 9,1k
12V:	R5 = 110k, R6 = 10k
15V:	R5 = 130k, R6 = 9,1k

voltage and divided again by 0.8. Specifically, with an output current of 100 mA at 9 V, the input current on the USB bus is approximately 225 mA. Finally, Figure 3 shows a small PCB layout for the circuit. All of the components except the connector and the terminal strip are SMDs.

Parts List:

(for UO = 9 V)
Resistors
R1,R2,R3 = 1Ω
R4 = 220kΩ
R5 = 82kΩ
R6 = 10kΩ
Capacitors
(SMD 1206)
C1 = 100nF
C2 = 2nF2
C3 = 22pF
C4 = 100nF
C5 = 1nF5
(tantalum SMD 7343)
C6 = 68μF 20V
C7 = 68μF 20V
C8 = 68μF 20V
C9 = 47μF 16V
C10 = 47μF 16V
C11 = 68μF 20V
Inductors
L1 = 820μH (SMD CD105)
L2 = 47μH (SMD 2220)
Semiconductors
D1 = SK34SMD (Schottky)
IC1 = LM3578AM (SMD SO8)
Miscellaneous
K1 = 2-way PCB terminal block, lead pitch 5mm
(optional)
K2 = USB-B connector

Wednesday, October 29, 2014

LM331 Frequency to voltage converter Diagram Circuit

Description.
LM331 is basically a precision voltage to frequency converter from National Semiconductors. The IC has a hand full of applications like analog to digital conversion, long term integration, voltage to frequency conversion, frequency to voltage conversion. Wide dynamic range and excellent linearity makes the IC well suitable for the applications mentioned above.
Here the LM331 is wired as a frequency to voltage converter which converts the input frequency into a proportional voltage which is extremely linear to the input frequency. The frequency to voltage conversion is attained by differentiating the input frequency using capacitor C3 and resistor R7 and feeding the resultant pulse train to the pin6 (threshold) of the IC. The negative going edge of the resultant pulse train at pin6 makes the built-in comparator circuit to trigger the timer circuit. At any instant, the current flowing out of the current output pin (pin 6) will be proportional to the input frequency and value of the timing components (R1 and C1). As a result a voltage (Vout) proportional to the input frequency (Fin) will be available across the load resistor R4.

Circuit diagram.

Notes.

The circuit can be assembled on a vero board.
I used 15V DC as the supply voltage (+Vs) while testing the circuit.
The LM331 can be operated from anything between 5 to 30V DC.
The value of R3 depends on the supply voltage and the equation is R3= (Vs – 2V)/ (2mA).
According to the equation, for Vs = 15V, R3=68K.
The output voltage depends on the equation, Vout = ((R4)/(R5+R6))*R1C1*2.09V*Fin.
POT R6 can be used for calibrating the circuit.

Sunday, October 26, 2014

3V to 40 Volt DC Converter Circuit

Switching regulator subsystems intended for use as dc to dc converters. 3V to 40 Volt DC Converter circuit | The use of switching regulators is becoming more pronounced over that of linear regulators because the size reductions in new equipment designs require greater conversion efficiency. Another major advantage of the switching regulator is that it has increasednapplication flexibility of output voltage. The output can be less than, greater than, or of opposite polarity to that of the input voltage.

The MC34063 series is a monolithic control circuit containing all the active functions required for dc to dc converters. This device contains an internal temperature compensated reference, comparator, controlled duty cycle oscillator with an active peak current limit circuit, driver, and a high current output switch. This series was specifically designed to be incorporated in step–up, step–down and voltage–inverting converter applications. These functions are contained in an 8–pin dual in–line package.

FEATURES 3V to 40 Volt DC Converter :
· Wide Input Voltage Range 3 V to 40 V
· Precision Internal Reference 2%
· High Output Switch Current Up to 1.5 A
· Short-Circuit Current Limiting
· Adjustable Output Voltage
· Low Standby Current
· Oscillator Frequency Up to 100 kHz

Saturday, October 25, 2014

Build 12V to 9V DC Converter

To get a more precise output voltage, replace zener diode Z1 with 10V and R1 with a 1Kilo ohm potentiometer. A Coolrib for Q1 is optional but highly recommended. You can replace Q1 for a more robust type to get more output amps depending on your requirements. Simple circuit to power your 9 volt cassette recorder and other stuff.

Parts List:

R1 = 560 ohm
C1 = 1000uF/40V, Electrolytic
C2 = 10uF/25V, Electrolytic
C3 = 330nF, Ceramic
Z1 = 9.1V, 1watt zener
Q1 = ECG184, NTE184

Thursday, October 23, 2014

Build a Converter VGA to BNC Adapter

There are monitors which only have three BNC inputs and which use composite synchronization (‘sync on green’). This circuit has been designed with these types of monitor in mind. As can be seen, the circuit has been kept very simple, but it still gives a reasonable performance. The principle of operation is very straightforward. The RGB signals from the VGA connector are fed to three BNC connectors via AC-coupling capacitors. These have been added to stop any direct current from entering the VGA card. A pull-up resistor on the green output provides a DC offset, while a transistor (a BS170 MOSFET) can switch this output to ground. It is possible to get synchronisation problems when the display is extremely bright, with a maximum green component.

In this case the value of R2 should be reduced a little, but this has the side effect that the brightness noticeably decreases and the load on the graphics card increases. To keep the colour balance the same, the resistors for the other two colors (R1 en R3) have to be changed to the same value as R2. An EXOR gate from IC1 (74HC86) combines the separate V-sync and H-sync signals into a composite sync signal. Since the sync in DOS-modes is often inverted compared to the modes commonly used by Windows, the output of IC1a is inverted by IC1b. JP1 can then by used to select the correct operating mode. This jumper can be replaced by a small two-way switch, if required.

VGA to BNC adapter PCB layout

This switch should be mounted directly onto the PCB, as any connecting wires will cause a lot of interference. The PCB has been kept as compact as possible, so the circuit can be mounted in a small metal (earthed!) enclosure. With a monitor connected the current consumption will be in the region of 30 mA. A 78L05 voltage regulator provides a stable 5 V, making it possible to use any type of mains adapter, as long as it supplies at least 9 V. Diode D2 provides protection against a reverse polarity. LED D1 indicates when the supply is present. The circuit should be powered up before connecting it to an active VGA output, as otherwise the sync signals will feed the circuit via the internal protection diodes of IC1, which can be noticed by a dimly lit LED. This is something best avoided.

Resistors:

R1,R2,R3 = 470Ω

R4 = 100Ω

R5 = 3kΩ3

Capacitors:

C1,C3,C5 = 47µF 25V radial

C2,C4,C6,C7,C10 = 100nF ceramic

C8 = 4µF7 63V radial

C9 = 100µF 25V radial

Semiconductors:

D1 = LED, high-efficiency

D2 = 1N4002
T1 = BS170
IC1 = 74HC86
IC2 = 78L05

Miscellaneous:
JP1 = 3-way pinheader with jumper
K1 = 15-way VGA socket (female), PCB mount (angled pins)
K2,K3,K4 = BNC socket (female), PCB mount, 75Ω

Wednesday, October 22, 2014

High Current Step Up Converter Using MAX641

High Current Step-Up Converter Using MAX641 integrated circuit, manufactured by Maxim IC, can be designed a very simple step-up converter using few electronic components. This step-up high voltage converter electronic projects allows a maximum output current up to 1A.

High Current Step-Up Converter Circuit Diagram

High Current Step-Up Converter Using MAX641

Low battery voltage detector input compare LB1 with internal reference of 1.31 V. LBO output goes in low state when the voltage at pin 1 falls below 1.31 V. The threshold voltage for "low battery", is determined by voltage divider R1-R2.

LED D1 illuminates the LBO output when the input voltage falls below 2.62 V.
Input voltage must remain below 5 V. The maximum effectiveness is 80% conversion.

Thursday, October 9, 2014

Light to Frequency converter circuit

The circuit is based on TLC555, the CMOS version of famous timer IC NE 555. A photo diode is used for sensing the light intensity.The timer IC is wired in astable mode.The leakage current of the reverse biased photo diode is proportional to the light intensity falling on it.This leakage current charges the capacitance C1.When the capacitor voltage reaches 2/3 of the supply voltage the out put (pin 3) goes low.As a result the capacitor discharges through photo diode .When the capacitor voltage reaches 1/3 the supply voltage the out put (pin 3) of IC goes high.This cycling continues and we get a frequency at pin 3 proportional to the light intensity falling on the photo diode.

Light to Frequency Converter Circuit Diagram & Parts List.

Light

Light to Frequency Converter Circuit Diagram

Notes.

With the given components the frequency varies from 1KHZ @ complete darkness to 24 Khz @ bright sunlight.The frequency range can be changed by using different values for C1.
Use any general purpose photo diode for D1.

Thursday, October 2, 2014

Digital to Analogue Converter DAC Circuit

The circuit of a 9-bit Digital to Analog Convener (DAC) is shown. This system combines the concepts of multiple·switch COS/MOS lCs, a low-cost ladder network of discrete metal-oxide film resistors, a CA313O op-amp connected as a follower, and an inexpensive monolithic regulator in a simple single power-supply arrangement. An additional feature of the DAC is that it is readily interfaced with COS/MOS input logic, e.g. 10- volt logic levels are used in the circuit.

The circuit uses an R/2R voltage- ladder network, with the output potential obtained directly by terminating the ladder arms at either the positive or the negative power-supply terminal. Each CD4007A contains three "inverters", each "inverter" functioning as a single-pole double- throw switch to terminate an arm of the R/2R network at either the positive or negative power-supply terminal. The resistor ladder is an assembly of one per cent tolerance metal-oxide film resistors. The five arms requiring the highest accuracy are assembled with series and parallel combinations of 806,000 ohm resistors from the same manufacturing lot. A single 15-volt supply provides at positive bus for the CA313O follower amplifier and feeds the CA3085 voltage regulator. A "scale-adjust" function is provided by the regulator output control, set to a nominal 10- volt level in this system. The line voltage regulation (approximately 0.2%) permits a 9-bit accuracy to be maintained with variations of several volts in the supply. The flexibility afforded by the COS/MOS building blocks simplifies the design of DAC systems tailored to particular needs.

Thursday, September 18, 2014

12 V Glow Plug Converter

Most small internal-combustion engines commonly used in the model-building world use glow plugs for starting. Unfortunately, glow plugs have an operating voltage of 1.5 V, while fuel pumps, starter motors, chargers and the like generally run on 12 V. This means that a separate battery is always needed to power the glow plug. The standard solution is to use an additional 2-V lead storage battery, with a power diode in series to reduce the voltage by approximately 0.5 V. However, this has the annoying consequence that more than 30 percent of the energy is dissipated in the diode. Naturally, this is far from being efficient.

Circuit diagram :
12-V Glow Plug Converter-Circuit Diagram

12-V Glow Plug Converter-Circuit Diagram

12-V Glow Plug Converter Circuit Diagram

The converter presented here allows glow plugs to be powered from the 12-V storage battery that is usually used for fuelling, charging, starting and so on. A car battery can also be used as a power source. Furthermore, this circuit is con-siderably more efficient than the approach of using a 2-V battery with a series power diode.

The heart of the DC/DC converter is IC1, a MAX 1627. The converter works according to the well-known step-down principle, using a coil and an electrolytic capacitor. Here the switching stage is not integrated into the IC, so we are free to select a FET according to the desired current level. In this case, we have selected a 2SJ349 (T1), but any other type of logic-level FET with a low value of RDSonwould also be satisfactory. Of course, the FET must be able to handle the required high currents.

Diode D1 is a fast Schottky diode, which must be rated to handle the charging currents for C2 and C3. This diode must also be a fairly hefty type. The internal resistances of coil L1 and capacitors C2 and C3 must be as low as possible. This ensures efficient conversion and prevents the components from becoming too warm.

The resistor network R2/R3 causes 87 percent of the output voltage to be applied to the FB pin of IC1. This means that an output voltage of 1.5 V will cause a voltage of approximately 1.3 V to be present at the FB pin. The IC always tries to drive the switching stage such that it ‘sees’ a voltage of 1.3 V on the FB input. If desired, a different output voltage can be provided by modifying the values of R2 and R3.

When assembling the circuit, ensure that C5 and C1 are placed as close as possible to IC1, and use sufficiently heavy wiring between the 12-V input and the 1-5-V output, since large cur-rents flow in this part of the circuit. A glow plug can easily draw around 5 A, and the charging current flowing through the coil and into C2 and C3 is a lot higher than this!

Author : P. Goossens

Thursday, August 21, 2014

Simple Analog to Digital Converter

Normally analogue-to-digital con-verter (ADC) needs interfacing through a microprocessor to convert analogue data into digital format. This requires hardware and necessary software, resulting in increased complexity and hence the total cost.

http://www.electronic-diagram-diagrams.com/computersimages/2.gif

The schema of A-to-D converter shown here is configured around ADC 0808, avoiding the use of a microprocessor. The ADC 0808 is an 8-bit A-to-D converter, having data lines D0-D7. It works on the principle of successive approximation. It has a total of eight analogue input channels, out of which any one can be selected using address lines A, B and C. Here, in this case, input channel IN0 is selected by grounding A, B and C address lines.Usually the control signals EOC (end of conversion), SC (start conversion), ALE (address latch enable) and OE (output enable) are interfaced by means of a microprocessor. However, the schema shown here is built to operate in its continuous mode without using any microprocessor. Therefore the input control signals ALE and OE, being active-high, are tied to Vcc (+5 volts). The input control signal SC, being active-low, initiates start of conversion at falling edge of the pulse, whereas the output signal EOC becomes high after completion of digitisation. This EOC output is coupled to SC input, where falling edge of EOC output acts as SC input to direct the ADC to start the conversion.
As the conversion starts, EOC signal goes high. At next clock pulse EOC output again goes low, and hence SC is enabled to start the next conversion. Thus, it provides continuous 8-bit digital output corresponding to instantaneous value of analogue input. The maximum level of analogue input voltage should be appropriately scaled down below positive reference (+5V) level.The ADC 0808 IC requires clock signal of typically 550 kHz, which can be easily derived from an astable multivibrator constructed using 7404 inverter gates. In order to visualise the digital output, the row of eight LEDs (LED1 through LED8) have been used, wherein each LED is connected to respective data lines D0 through D7. Since ADC works in the continuous mode, it displays digital output as soon as analogue input is applied. The decimal equivalent digital output value D for a given analogue input voltage Vin can be calculated from the relationship

Monday, August 18, 2014

Temperature To Frequency Converter Wiring diagram Schematic

This is a simple Temperature To Frequency Converter Circuit Diagram. enables the schema to be used as a reliable temperature-to- frequency converter; in combination with the fixed reference output of 1.00 V, offset scales. This In this schema an LM34 or LM35 produces a frequency proportional to temperature. Reference current (138 ) is set via R3. The output can be used to drive a display, frequency counter, or other indicating device for temperature readout.

Temperature To Frequency Converter Circuit Diagram

Temperature

Sunday, August 10, 2014

400V 60W Push Pull DC DC Converter Wiring diagram Schematic

The TL494 switching regulator governs the operating frequency and regulates output voltage. Switching frequency approximately 100 kHz for the values shown. Output regulation is typically 15% from no-load to full 60 W.

400V-60W Push-Pull DC-DC Converter Circuit Diagram

400V-60W Push-Pull DC-DC Converter Circuit Diagram

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