Free electronic circuit design and schematic diagram
The bias path can compromise the high input impedance you would otherwise get with an op-amp as with transistors amplifiers. This particularly with ac-coupled inputs where a resistor to ground is mandatory. The bootstrap circuit shown below is a possible solution if that is a problem. The 1mF capacitor makes the upper 100k resistor look like a high impedance current […]
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This is a Shunt Series Pair Wideband Amplifier circuit. This circuit has four feedback loops, they are two emitters feedback, shunt-shunt feedback and an AC feedback loop(series-shunt). This is a very stable circuit and can be used for wideband amplifiers and low gain. This circuit requires +12 supply that restrict the “headroom” of the second resistor. The emitter of the […]
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This is Complementary Pair Vertical Deflection Pre-Amplifier circuit. This circuit is modification circuit of Vertical Deflection Pre-Amplifier for 100MHz scope. This circuit remove few resistor-capacitor combination from the original circuit. That components can be removed because they tweaked the response of the amplifier at high frequencies, so no problem. The second two transistors receive +2V from the two 1N4733 5.1V […]
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This schematic diagram below shows a Digitally Controlled Dual Polarity Amplifier circuit. The circuit (a) can give a means of amplifying a signal either in non inverting and inverting mode. When S2 is off and S1 is on, the noninverting input of the op amp is fed by the signal. The circuit behaves as a regular inverting amplifier, When switch […]
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This is a microphone pre-amplifier circuit that use discrete components. The gain of this circuit is 100 and should be enough for most microphones. It is set by the ratio of the 10k resistor to the 100R. As common-emitter amplifiers, This circuit uses two directly coupled transistors. Here is the schematic diagram of circuit: Please note that this circuit has […]
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This is simple circuit for Guitar Pre-Amplifier. This circuit has some advantages such as it will work under tough conditions, very simple and has high input impedance. This circuit will not load down electric guitars because of the high input impedance. This circuit can be used to amplify microphones. Here is the circuit:A 9-volt battery is typically used as power […]
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Junction field effect transistors can give exceptionally low input currents when they are used on the input stage of an operational amplifier for ambient temperatures less than about 70’C. However, since it is no simple matter to diffuse high quality FET’s on the same chip as the amplifier , there is no monolithic FET amplifiers available now. Nonetheless, create a […]
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