Circuit Project Electronic

LM311 is a comparator,
It operates from single 5V supply or dual supplies, input current 150 nA, 50 V-50 mA output drive capability. TTL-CMOS compatible output.
The Output is open collector so it can sink current but cannot source, a totem pole output can source and sink. In this Circuit R2 is the source or pull-up.
The Output [...]

The left half of the 556 dual timer IC is used as a fixed frequency square wave oscillator. The oscillator signal is fed into the right half of the 556 which is configured as a variable pulse width one-shot monostable multivibrator (pulse stretcher). The output of the one-shot is a variable width square wave [...]

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This circuit provides 0-30 volts, at 1 amp, maximum, using a discrete transistor regulator with op-amp feedback to control the output voltage. This power supply has constant current mode suitable for charging batteries.
With reference to the schematic, lamp, LP2, is a power-on indicator. The other lamp (lower) lights when [...]