Normal multimeter cannot check it. This circuit can help you.
IC-555 timer is an integrated circuit used for timer, pulse, oscillator application. They can be used to the time delays, flip-flop. They have 8 pins so easy, and small circuits.
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These are many Monostable multivibrator using 555 timer. We use it as timer for control a load, LEDs,driver relay. Which trigger them using a normal switch. [...]
This is police siren circuit using 555 IC, with PCB layout, using 2 IC-555 as frequency oscillators and transistor to drive sound to the speaker [...]
This is a simple pulse generator circuit or standard astable oscillator circuit for IC 555 timer,NE555N IC. Use for digital Logic circuit.
This is 555 audio simple ohmmeter circuit. Some times, we need to measure roughly resistances only. we can know resistances by audio also fast check. [...]
The simple bounceless switch circuit. It is one kind of electronic switches, high quality, and low noise. They are suitable for the digital circuits. Why?
This is Simple 555 Alarm sound circuit, for beginner as buzzer sound. IC1 is pulse generator, to transistor PNP for boost current to speakers.