Free Simple Circuit Diagram
The following touch switch circuit uses a CA3240 dual BiMOS op amp to sense small currents flowing between the contact points on a touch plate. Since this circuit is directly coupled with line voltage, a 1 M resistors in series with the touch plates is employed to ensure user safety, avoiding hazardous high voltage shock. This high resistor values is […]
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The following two-transistor circuit is a pre-amplifier circuit for magnetic phono cartridge, which is characterized by its frequency response defined by RIAA standard for phono recording. This pre amp circuit has gain around 40 dB (midband) at 1 kHz. Here is the schematic diagram of the circuit: [Circuit’s schematic diagram source: seekic.com]
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To save the complexity of driver circuit, a multiplexer icrcuit can be used for the solution. With this multiplexed BCD decoder, we can use only one BCD decoder to drive 3-digits 7 segment display. Each digit will be activated in sequence, but it will look like that all digits are driven continuously since the sequence is repeated quickly. Here is […]
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555 IC is very popular component for timer circuit. With integrator circuit, we can extend the timing period of 555IC timer with reasonable capacitor size. With conventional 555IC timer configuration, the timing capacitor will be large compared to integrator version. You can see the comparison in the graph below the schematic diagram. [Circuit’s schematic diagram source: seekic.com]
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