Monday, April 5, 2010

Timers and Time Delay Relays


Time Delay Relays
Time Delay Relays all include a combination of a solid state timing circuit and an electromechanical relay output. This combination provides the user with isolation between the operating and load voltages and multiple switching contacts in either SPDT or DPDT forms. Most of the relay contacts are rated 10 amps resistive @ 240 VAC. Many are in the popular octal plug-in package and require the purchase of a socket. Others surface mount with one or two screws and have male 0.25" quick connect terminals. Some are encapsulated to protect the solid state circuitry. A large selection of time delay ranges and adjustment methods are available.

Timing Modules
All popular functions are available in this group of totally solid state timing modules. They contain no moving parts so 100 million operations is typical. They are encapsulated to protect their analog or digital solid state circuitry. A large selection of time delay ranges are available, knob or switch adjustment, or external adjustment, or factory fixed time delays can be ordered.

Some timer and timer delay modes of operation:

DELAY ON MAKE
(On Delay, Delay on Operate, Operate Delay, Prepurge Delay)

OPERATION/TIME DIAGRAM
OPERATION: Upon application of power, the time delay begins. The output is de- energized before and during the time delay. At the end of the time delay, the output is energized (relay is transferred) and remains energized until power is removed.

RESET: Removing power resets the time delay and output.


INTERVAL
(On Interval, Interval On, Pulse Shaping, Bypass Timing)

OPERATION/TIME DIAGRAM
OPERATION:Upon app
lication of power, the time delay begins. The output is energized (relay is transferred) during the time delay. At the end of time delay, the output is de-energized and remains de-energized until power is removed.
RESET: Removing power resets the time delay and the output.

RECYCLING

(Recycle Timing, Repeat Cycle, Duty Cycling)

OPERATION/TIME DIAGRAM (ON TIME FIRST)

OPERATION: Upon application of power, the output is energized (relay is transferred) and the ON time begins. At the end of the ON time, the output de-energizes and the OFF time begins. At the end of the OFF time, the output is energized and the cycle repeats as long as power is applied. The OFF time may be the first delay in some recycling timers.

RESET:
Removing power resets the output and time delays, and returns the sequence to the first delay.

SINGLE SHOT
(One Shot Relay, Single Shot Interval, Pulse Shaping)

OPERATION/TIME DIAGRAM
OPERATION:Power must be applied to the input before and during timing. Upon momentary or maintained closure of the initiate sw
itch (leading edge triggered), the output is energized (relay is transferred) for a measured interval of time. At the end of the delay, the output de-energizes. Opening or reclosing the initiate switch during timing has no effect on the time delay.

RESET:
Reset occurs when the time delay is complete and the initiate switch is opened. Loss of power resets the time delay and output.

DELAY ON BREAK

(Off Delay, Release Delay, Delay on Release, Postpurge Delay)

OPERATION/TIME DIAGRAM


OPERATION:Power must be applied to the input before and during timing. Upon closure of the initiate switch, the output is energized (relay is transferred). The time delay begins when the initiate switch is opened (trailing edge triggered). The output remains energized during timing. At the end of the time delay, the output is de-energized. The output will energize if the initiate switch is closed when power is applied.

RESET:Reclosing the initiate switch during timing resets the time delay. Loss of power resets the time delay and output.