Showing posts with label converter. Show all posts
Showing posts with label converter. Show all posts
Sunday, October 26, 2014
TC9400 IC Frequency to Voltage converter Diagram Circuit
Description.
A very simple and low cost frequency to voltage converter based on the TC9400 IC from Microchip is shown here. TC9400 can be either wired as a voltage to frequency converter or frequency to voltage converter and it requires minimum external components. The functional blocks inside the TC9400 includes integrator opamp, 3uS delay circuit, one shot circuit, charge discharge control circuit, divide by 2 network and necessary drivers. This circuit finds application in a range of electronic projects like frequency meters, tachometers, speedometers, FM demodulators etc.
A very simple and low cost frequency to voltage converter based on the TC9400 IC from Microchip is shown here. TC9400 can be either wired as a voltage to frequency converter or frequency to voltage converter and it requires minimum external components. The functional blocks inside the TC9400 includes integrator opamp, 3uS delay circuit, one shot circuit, charge discharge control circuit, divide by 2 network and necessary drivers. This circuit finds application in a range of electronic projects like frequency meters, tachometers, speedometers, FM demodulators etc.
Circuit diagram.
TC9400 Voltage to Frequency converter (Single supply version)
In the circuit shown above the TC9400 is wired as a F to V converter that operates from a single supply. The circuit generates an output voltage that is proportional to the input frequency. The input frequency is applied to the pin11 (non inverting input of the internal comparator). In order to trip the comparator the amplitude of the input frequency must be greater than +/-200mV.Below this level the circuit will not work at any situation.
Whenever the input signal to the pin 11 of IC1 crosses zero to the negative direction the output of the internal comparator goes low. The 3uS delay circuit enables the Cref charge/discharge circuit after 3uS and this connects the Cref to the reference voltage and this charges the integrating capacitor Cint a specific amount of voltage. In the single supply operation the reference voltage is the potential difference between pin 2 and 7 of the TC9400. Each time the input frequency wave form crosses zero towards positive direction, the output of the internal comparator goes high and this disables the Cref charge/discharge circuit which creates a short circuit across the Cref leads. The voltage across the integrating capacitor Cint is retained because the only discharge path available is the 1M resistor Rint which is a too high and the voltage across Cint is the output voltage. Resistor Rbiasis used to set the bias current of the IC.
The potential divider network comprising of R6 and R7 makes sure that the input threshold tracks the supply voltage always. The clamp circuit using diode D2 prevents the input from going far negative in order to turn on the internal comparator. In simple words this section of the circuit can be generally termed as a level shifter.
The TC9400 manufacturers claim that it can accept a signal of any frequency at its input. In the practical side, for the proper working of this circuit the positive half of the input signal must have at least 5uS pulse width and for the negative half it must be greater than or equal to 5uS.
For calibration adjust the offset adjust trimpot to obtain 0V at the output with no input frequency applied. If you have a function generator, set frequency input to 10KHz and make adjustments in the value of Cref to get around 2.5 to 3 volts at the output. This calibration is meant for a maximum input frequency of 10KHz.
Notes.
- The circuit can be assembled on a Perf board or PCB.
- The circuit can be powered from anything between 10 to 15V DC.
- R3 can be used for adjusting the offset voltage.
- In the circuit the inverting input of the internal comparator is referenced to 6.2V by using D1. So the input signals amplitude must be between 4V and the supply voltage (V+).
- The output voltage is also referenced to 6.2V in this circuit.
- The output voltage and input frequency of the F to V converter is related using the equation V out = V ref x C ref x F in where V out is the output voltage and F in is the input frequency.
- TC9400 and TL071 must be mounted on holders.
Saturday, October 18, 2014
6 to 12 Volt Converter
Below its a converter circuit voltage from 6 Volt to 12 Volt DC.
 |
| 6 Volt to 12 Volt DC |
Part List :
R1, R4 2 .2K 1/4W Resistor
R2, R3 4.7K 1/4W Resistor
R5 1K 1/4W Resistor
R6 1.5K 1/4W Resistor
R7 33K 1/4W Resistor
R8 10K 1/4W Resistor
C1,C2 0.1uF Ceramic Disc Capacitor
C3 470uF 25V Electrolytic Capcitor
D1 1N914 Diode
D2 1N4004 Diode
D3 12V 400mW Zener Diode
Q1, Q2, Q4 BC547 NPN Transistor
Q3 BD679 NPN Transistor
L1 See Notes
Notes
1. L1 is a custom inductor wound with about 80 turns of 0.5mm magnet wire around a toroidal core with a 40mm outside diameter.
2. Different values of D3 can be used to get different output voltages from about 0.6V to around 30V. Note that at higher voltages the circuit might not perform as well and may not produce as much current. You may also need to use a larger C3 for higher voltages and/or higher currents.
3. You can use a larger value for C3 to provide better filtering.
4. The circuit will require about 2A from the 6V supply to provide the full 800mA at 12V.
Sunday, September 7, 2014
Build a 12V to 9 or 6 v Converter Wiring diagram Schematic
Build a 12V to 9 or 6 v Converter Circuit Diagram. This 12V to 9 or 6 v Converter Circuit Diagram enables transistorized items such as radio, cassettes, and other electrical devices to be operated from a car`s electrical supply.
The table gives values for resistors and specified diode types for different voltage. Should more than one voltage be required a switching arrangement could be incorporated. For high currents, the transistor should be mounted on a heat-sink.
12V to 9 or 6 v Converter Circuit Diagram
Wednesday, September 3, 2014
12 Volt to 32 Volt CT converter DC to DC
Kit that can change the normal 12v dc voltage from a car battery, battery bike 12V motor. With the current 7A. so this circuit is very suitable for power car amplifiers and sound systems that use simple 12V battery.
Kit converter is also equipped with inputs "SEND" to activate the circuit and also send this interchangeable inputs is connected to the Tape / cd / dvd player of your car. And input "send" is if the non-connected with an output of "send" player car you then connect it to +12 hrs on v from the battery / batteries The series is already in the test kit and has been functioning normally.
Kit converter is also equipped with inputs "SEND" to activate the circuit and also send this interchangeable inputs is connected to the Tape / cd / dvd player of your car. And input "send" is if the non-connected with an output of "send" player car you then connect it to +12 hrs on v from the battery / batteries The series is already in the test kit and has been functioning normally.
Thursday, August 28, 2014
Offline Converter Wiring diagram Schematic
This nonisolated, unregulated, minimum component converter fills the void between low-power zener regulation and the higher power use of a 60-Hz input transformer. It is intended for use where)`er a nonisolated supply can be used safely.
The schema operates~by conducting only during the low-voltage portion of the rectified sine wave. Rl and D2 charge Cl to approximately 20 V, which is maintained by Ql. This voltage is applied to the gate of Q2, turning it on. When the rectified output voltage exceeds the zener voltage ofD4, Ql turns on, shunting the gate of Q2 to ground, turning it off.
Offline Converter Circuit Diagram
Sunday, August 17, 2014
Buck Converter 1 Watt White LED Driver
This is an example of efficiently driving a 1 watt white LED from a 12 volt battery using a buck converter. The LED could simply be connected with a series resistor to get the desired current, but the efficiency would be only 25% since the resistor would drop 9 volts while the LED only requires 3. The buck converter provides about 90% efficiency. The idea is to establish a circulating current through the inductor, diode and load, while the switch replenishes the lost load energy on each cycle. The duty cycle of the switch will be the output voltage divided by the input voltage, or about 3/12 (25%) in this case. Its actually a little greater since there is a small (2.2 ohm) resistor in series with the LED that drops about 0.5 volt, so the total load is about 3.7 volts and the duty cycle is around 31%. The schema could also be used to charge AA batteries from a 12 volt source with adjustment to the duty cycle. The driver section uses a CMOS hex inverter (CD4069) where two of the inverters form an oscillator with 31% duty cycle at about 11.5 Khz, or 66us off time, and 21uS on time for the MOSFET switch. The remaining 4 inverters are used in parallel to provide additional drive current to the gate of the MOSFET. The duty cycle can be adjusted with either the 15K or 20K resistors. The minimum inductor value was worked out from E = L * di/dt and a LED current of 250mA. The minimum value is where the current falls to 0 during the switch off time, or 66uS. The peak inductor current would then be twice the average or 500mA and the inductor will charge from 0 to 500mA in 21uS. So, di/dt is 0.5 /.000021 = 23810 amps per second. The inductor voltage (E) will be 12 minus the load voltage 3.7 or 8.3 volts and the minimum inductor value L will be 8.3 / 23810 = 0.35 mH. The actual value used should be somewhat higher to avoid the current falling to zero and to avoid large peak currents and possible saturation. The example here uses a approximate 2 mH inductor so the change in current is about 100mA and the peak current is lower at about 300mA. The current waveform is shown in the LTspice picture below. Notice the current ramps from about 50mA below the average current to about 50mA above the average or about 100mA total change. The 15 ohm resistor in the LTspice picture represents the LED plus a 2.2 ohm resistor. The MOSFET is represented by the SW (switch) component, and the drive schema by the V3 symbol.
The inductor (pictured below) should be rated for saturation current of more than the peak current, or maybe 300mA in this case. The toroid inductor used is fairly large for the task measuring about 1.5 inches diameter with 20 turns of #18 wire. The core is conductive so it probably should be taped in case the wire insulation fails. The picture shows the naked core for illustration. A smaller core with an air gap could be used to avoid saturation, but would require more wire which would add to the losses due to the wire resistance. Another approach is to use a higher frequency so smaller inductors can be used. But this will add to losses since there would be more switching transitions per unit of time, which adds to the loss. The diode is a VSK330 schottky 3 amp variety for low loss, but most any 1 amp rectifier could be used with somewhat less efficiency. The IRFZ44 MOSFET is also an overkill rated at 50 amps max but very low on-resistance of only 28 milliohms. A much smaller device could be used, but I dont have the numbers. Note the schema has no regulation, so the 12 volt input should be stable. If the battery voltage varies, the duty cycle and LED current should be set using the highest expected supply voltage.
link
Sunday, August 10, 2014
Current to Voltage Converter Wiring diagram Schematic
A filter removes the dc component of the rectified ac, which is then scaled to RMS. The output is linear from 40 Hz to 10 kHz or higher.
Current to Voltage Converter Circuit Diagram
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