FLASHING INDICATORS 555 timer circuits

This is a request from Daniel, one of our subscribers. 
He needed to flash "turn indicators" using a 555 and a single 20 amp relay. Here is our suggestion. The timing resistor needs to be selected for the appropriate flash-rate. 

SIREN 100dB 555 timer circuits

This is a very siren and if two or more piezo's are located in a room, the burglar does not know where the sound is coming from, A robber will not stay anywhere with an ear-piercing sound as he cannot hear if someone is approaching, It's the best deterrent you can get. The "F" contact on the piezo is "feedback" and is not needed in this 555 timer circuits.

PWM Controller 555 timer circuits

This 555 timer circuits to controller will deliver up to 30 amps and control the motor from 5% to 95%. 

Stepper motor controller 555 timer circuits

This 555 timer circuits for circuit controls the speed of a stepper motor via the 100k pot, The direction of rotation is determined by the double pole double throw switch, stepper motor used in this circuit came from an old scanner. It had 5 wires: red-black-yellow-brown-orange,LED illuminate via the back-emf of the coils and prevent the spikes entering the transistors. The LED will flicker to show the pulses being received by the stepper motor, 27k stop-resistor limits the upper-frequency of the 555 and prevents the circuit producing pulses that are too fast for the stepper motor.