1.

2. Off Delay (delay on release) timer

• -is a device which does not start its timing

• function until the power is remove from the

• timer

• -when control switch is close, the timer

• contact change immediately and provide

• power to the load.

• -Time period start counting when the power

• is removed from the timer.

• -timer return to its normal position (switch

• open) whenever time period,T is achieved

• and the load de-energized.

3. Off Delay

• -maybe used to provide cooling in a

• projector once the bulb has been turn off

• but has no time to cool down.

• -closing switch S1 will turn ON the

• projector bulb and activate timer coil

• TR1.

• -Normally open contact TR1 will

• immediately close energize fan motor

• which control the cooling of the

• projector.

• -When S1 open, will turn off the projector lamp &

• power is removed from the timer.

• -Contact TR1 is remain closed for a period time, T

• and open after the predetermined period is

• passed .Cooling fan motor turn off.

4. One shot(interval) timer

• -is a timer where contact change position

• and remain change for the set period of

• time after timer received power.

• -is used which load is ON for period set

• of time.

5. Application of one shot timer.

• -use in application which require ON and

• OFF time period.

• -in this case, it use for control the amount

• of time the plastic wrap is wound around

• a pallet of carton.

• -photoelectric switch detect pallet enter

• plastic wrap machine.

• -Once detected, one shot timer will

• activated, contact close start wrapping

• process.

• -Wrapping process continues for the

• setting of the timer.