At the end of this chapter we should able to: •Identify the main function of a solenoid. •Identify the application of solenoid. •Describe the application of solenoid with operating valves. •Draw the symbol of a solenoid with a standard symbol. •Draw a control circuit showing the energizing of a solenoid through the closing of relay contact, using acontrol relay, two push button switches and a solenoid.
Solenoid is an electromechanical deviceElectrical energy is used to magneticallycause mechanical movement
Single Solenoid Spring Return Valve Operating the START push-button switch close the circuit to the coil of relay ICR. The coil is now energized. Relay contact 1CR-1 then closes, interlocking around the START push-button switch. Contact 1CR-2 closes, energizing solenoid A. The circuit can be de-energized by operating the REVERSE push-button switch. 1 CR-1 START REV 1 CR 1 3 4 2 1 CR-2 SOL A 1 5 2
Single Solenoid Spring Return Valve Time-delay relay is added. Operating the START push button switch closes the circuit to the coil of relay 1 CR. The coil is now energized. Contact 1 CR-1 closes, interlocking around the START push button switch. Contact 1CR-2 closes, energizing solenoid 1A. Contact 1CR-3 closes, energizing the coil of timing relay 1TR. After a time delay, as set on the timing relay, the timing constant contact closes, energizing solenoid 1B. The circuit can be de-energized by operating the REVERSE push button switch.
Applied in many electrical activated devices such as Valves Locks Punches Marking machines
Common Rotary Solenoid Circuit breakers IC insertion machines Defibrillators Textile machinery Automatic tellers Film processors Machine tools Pinch rollers Brakes Ticket machines Copiers
Common Linear Solenoid Vending machines Brakes Copiers Door locks Pumps Interposers Coin changers Film processors Disk drive locks Electronic typewriters