Rongge

This circuit demands a control current that is 100 times smaller than that needed by a typical optically isolated solid state relays. It is ideal for battery-powered systems. Using a combination of a high current TRIAC and a very sensitive low current SCR, the circuit can control about 600 watts of power to load while providing full isolation and transient protection. Sourced by :link

Description This temperature controlled relay circuit is a simple yet highly accurate thermal control circuit which can be used in applications where automatic temperature control is needed. The circuit switches a miniature relay ON or OFF according to the temperature detected by the single chip temperature sensor LM35DZ.  When the LM35DZ detects a temperature higher than the preset level (set by VR1), the relay is actuated. When the temperature falls below the preset temperature, relay is de-energized. The circuit can be powered by any DC 12V supply or battery (100mA min.)   Circuit Diagram How it works? The heart of the circuit is the LM35DZ temperature sensor which is factory-calibrated in the Celsius (or Centigrade) scale with a linear Degree->Volt conversion function. The output voltage (at pin 2) changes linearly with temperature from 0V (0 o C) to 1000mV (100 o C). The preset (VR1) & resistor (R3) from a variable voltage divider which sets a reference voltag...

This is a Relay activated by Sound Circuit Diagram . Generally a circuit has a basic function, but according to our needs can modify or add to a circuit making it more complex. This circuit is a relay activated by sound, which can be used in an alarm system, home automation, robot and even in an Arduino. Undoubtedly this control by sound can be very useful, an example is a light activated by the sound of a knock on the door or a round of applause. The light turns off automatically after a few seconds. An alternative is to use protection against theft - if someone wants to open the door or break something light illuminates, indicating that someone is home. The circuit can work with any voltage 5-12 Vdc, it depends on the voltage of the relay coil. Relay activated by Sound Circuit Diagram

The circuit above is  a circuit of drivers to control high voltage using the relay. Relay is controlled by an NPN transistor , its that works on 5V voltage and has diode in it, if the relay does not have s diode should be given with diode 1N4007 . Pin relay to  move the switch connected to V+ 5V and other is connected from driver NPN transistor , the base od the transistor may have input such us from circuit of infrared to control the distance, or with some other input. After the transistor was input  and the collector had output a voltage of the switch relay will work, and voltage that in switch relay ready to use. To cut off switch eliminates enough voltage input at the base transistor , the collector will not remove the voltage , and switch are automatically disconnected.