Single Transistor Relay Toggle Circuit The circuit below requires a double pole, double throw relay in conjunction with a single transistor to allow toggling the relay with a momentary push button.[...]
Relay Toggle Circuit Using a 556 Time This toggle circuit operates by using a couple 555 timers wired as inverters. Pins 2 and 6 are the threshold and trigger inputs to the first timer and pin 5 is the output. [...]
Relay Toggle Circuit Using a 555 Timer
This 555 timer circuit below toggles a relay when a button is pressed. Pins 2 and 6, the threshold and trigger inputs, are held at 1/2 the supply voltage by the two 10K resistors….[...]
Single MOSFET Relay Toggle Circuit This circuit is similar to the one above, but uses a N channel mosfet such as IRF530, 540, 640, etc. in place of the NPN transistor. Smaller mosfets could be used, but I don’t know the part numbers.[...]

Simple Tone Oscillator Generator by 2N2222 This is Simple Tone Oscillator Generator. It is use transistor 2N2222 and 2N2907 be main part. By control tone sound with R2 – 50K and use 8ohm ….
Tone Generator by 2N4891 This be Basic Tone Generator by UJT Transistor 2N4891 numbers. By it s can give with small-sized loudspeaker s have a voice electric loud bell moderately….
Tone Burst Generator by LM555 Friends take an interest try build Tone Burst Generator be simple is. Try this circuit like sure because use IC 7555 , highly popular again. Assure that not sure difficult press the the secretariat of the…
Stereo Test Tone Generator with LM324 and LM1458 The purpose of this circuit is to create a pair of sine waves for testing stereo equipment. While it is useful for many types of audio test tone generation, the circuit is specialized for the purpose….