Category «Control and Monitoring»

Sound-Controlled Relay

This is a relay circuit that detect the presence of sound to activate the relay. You can use this sound-controlled relay as voice operated switch, light control, toys, or any other application that can be controlled by a switch. Just replace the switch with  this relay and now you have a sound-controlled device. This circuit …

Logic Power Control for 78xx Regulator

Logic power control of analog regulator can be useful in application where a digital circuit/controller need to control power source, such as in EEPROM programmer or other power controls.  This is a circuit provide ON-OFF control  for 78xx regulator using digital (TTL or CMOS) signal level. This circuit uses transistors in series with the 78XX …

Touch Switch Monostable/Timer with 555 IC

A schematic diagram of a touch switch circuit is shown below. This circuit consist of timer, one shoot multivibrator and touch terminal. As timer, this circuit uses 555 timer which is connected to one-shot multivibrator. The touch terminal is used to trigger this circuit. The output of this  circuit can be used to drive a …

2 Phase and 3 Phase Motor Drivers

The schematic diagram below show 2-phase and 3-phase motor driver circuits. This circuit can used to drive an AC motor because this circuit has an integrated power operational amplifier, built-in power-output stage and high amplification factor. The needed AC signal is produced by the op amp that is configured as oscillator. The motor is driven …