Free electronic circuit design and schematic diagram
This flip-flop circuit is a free running/astable multivibrator one, with bases and collector of both emitter biased transistor are directly coupled to each other. Switching action is supported by means of capacitor in each emitter circuit. This configuration produce a triangle waves at emitters. Since neither transistor can remain permanently cut off, then a free running oscillation will be generated. […]
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This audio mixer circuit doesn’t use a low impedance input to mix no ideal sources, but use many amplifiers to provide ideal sources before mixed through simple resistors. Ideal source means a sources with low impedances, make the interaction between signals in the output doesn’t affect the input. Please note that this mixer circuit has high impedance output, so you’ll […]
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On this following circuit shown in the schematic diagram, two MAX455s IC chip are cascaded to build a 1 of 15 video Multiplexer. This cascading is done by connecting the output of one MAX455 MUX to one input of a second MAX455 MUX. The output of the first MUX should be terminated to ground using a 75R resistor, to preserve […]
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This AM receiver consists of a TDA7000 single-chip FM receiver (U1) as the main radio component, and an LM386 chip for low-voltage audio-power amplifier (U2) circuit. The receiving coils are hand-wound coils (L1 and L2), and a few additional components. This coils, together with the variable capacitor, is chosen to match the AM frequency. To wind your won coil, L1 […]
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Relays are normally operated at current level where it can initiate the mechanical metal contactors movement. After contacts has been established, the current level needed to keep the conductor plates stay attached is actually smaller than the current to initiate it. This power saver circuit seems to have opposite mechanism of surge protector. This circuit provide surge current to initiate […]
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This doorbell circuit produces a low tone that will slide up to higher frequency. The equivalent total resistance connected between the base of Q1 and ground (Rbg) , and coupling capacitor C1 determines the AF oscillator’s frequency. The resistance (Rbg) is equal to (R2+R1)R3. Here is the schematic diagram of the circuit: The R2 is used to set the initial […]
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