Shunt Regulator | Electronic Project Circuits

Posts Tagged ‘shunt regulator’

15V Reducing Voltage Regulator Noise

The following circuit is designed for filtering 15 volt supplies like those typically found in instrumentation. The shunt will greatly reduce white noise, spurious signals, and line-related signals on the power supply; the attenuation can exceed 40 dB with careful construction. The values are not critical except that the gain of the amplifier should be very near the ratio of the transistor emitter resistor to the series shunt resistor. In this case the gain is 15/0.05 = 300. Actually the gain is 301 with the indicated values so a 299k resistor would be theoretically better but the resistor tolerances and the actual resistance in the 0.05 ohm shunt path will cause more variation. One of the gain resistors may be made variable to allow the performance to be tweaked for the deepest null, if desired. Choose a low noise metal foil or wirewound potentiometer for best results. Standard fixed values will give excellent noise reduction sufficient for most applications. The LM833 is an excellent choice but many other low noise op-amps will work well. Choose an op-amp with a high bandwidth and low input noise voltage. A higher value shunt resistor may be used if the voltage drop can be tolerated; adjust the gain of the amplifier to match as described above. The LM833 is a dual op-amp so two shunts may be implemented with the one package for filtering two different supplies or for cascading two shunts for additional line rejection and noise reduction. The noise shunt provides no load rejection beyond the rejection provided by the source regulator through the 0.05 ohm resistor.

Read More Source: http://www.techlib.com/electronics/finesse.html
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Be the first to comment - What do you think? Posted by admin - February 24, 2008 at 10:14 am

Categories: Power supply Tags: 15V voltage Regulator, dc voltage regulator, Filter, Low noise circuit, shunt regulator

Dynamo Current and Voltage Regulator by TL084

Let’s start analyzing the circuit in idle condition, when the engine is stopped. The battery voltage at B+ cannot pass to D+, because D1 blocks it. D+ is at ground level, because of the low resistance of the dynamo between D+ and D-. Q1 is biased off, which leaves the negative side of the entire OpAmp circuit floating. So the complete control circuit will float at +12V, and in this way will bias Q4 fully on. Q4 then holds DF down to ground, ready for dynamo startup, and for using the dynastarter as a starter.

There will be no power consumption other than the very low leakage of some components. Q1 is off, D1 and D5 are reverse biased, Q3 is off, D7 stays far below its conduction voltage, Q4 has an insulated gate, C1 and C8 supposedly don’t conduct DC… Actually, the leakage in C8 is the main current drain, but this leakage gets down into the microampere range when the circuit is connected permanently to the battery. So, this circuit consumes essentially no idling current, while keeping DF grounded for easy dynamo startup.

Read More Source:http://ludens.cl/Electron/dynareg/dynareg.htm
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Be the first to comment - What do you think? Posted by admin - February 9, 2008 at 5:49 pm

Categories: Electronic Control, Power supply Tags: bicycle dynamo circuit, shunt regulator, solar cell, TL084

Solar panel voltage regulator by LM358 , TIP142

Here is the schematic diagram of my regulator. You may want to print it out, and then go on reading. This regulator is designed for 12V systems employing panels of up to 7A total current, and loads of not over 20A. It can be easily modified for greater currents.

U1A compares an adjustable sample of the present battery voltage to a 5V reference from a highly stable source. According to the result, it controls the power transistors Q1 and Q2, which shunt off the excess power generation from the panel. A diode (D1) avoids battery voltage to go back to the panel under no-light condition. To avoid imprecise voltage control due to varying diode drop, the sample is taken from the battery side, even if this means a very small power waste.

The power resistors R1 and R2 are dimensioned in such a way that under maximum shunting, these resistors will dissipate almost all power (about 100W total), leaving the transistors running cool. The highest dissipation in the transistors happens when the regulator is dissipating half of the panel output; in this case, each transistor will dissipate about 12W.

Read More Source:http://ludens.cl/Electron/solarreg/Solarr%7E1.htm
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