circuit boards are based on the 555 and 556 Timer chips.
Times are controlled with “timing resistors” which are
easily replaceable by the user. Time intervals can
range from less than a second to about 50 minutes. See Info Sheets for a table
of resistor values and associated time delays.
Boards will come with short-interval timing resistors
installed for demonstration purposes. User will supply
timer resistors appropriate for their application -
available at any electronics supply store (i.e., Radio
Shack). All boards are powered by 12VDC. Other
voltages are available on request.
Time Delay Relay Board: $13.00
Here is a board that, when triggered, will activate
a relay for a specified period of time. This time
is controlled by a “timing resistor” which is easily
replaceable by the user. The trigger can be a
switch closure (supplied by User) or if you remove
the “pullup resistor” (see diagram on Info Sheet),
the board can be triggered by touching your finger
to wires coming from the trigger terminals.
Interval Timer Relay Board: $15.00
Here is a board that, when power is applied, will
cycle on and off a relay. The relay on time and off
time can be independently controlled. The
relay will continue cycling on and off until the
power to the board is turned off.
Cascading Timer Relay Board: $20.75
Here is a board with two 10A relays that, when
triggered, will activate one relay for a specified
time and then activate another relay for a specified
time. Each relay’s ON time can be independently
Once the second
relay’s time has expired both relays will remain off
until the board is triggered again.
Multi-Event Timer Relay Board:
Here is a board that I developed for someone who set
up haunted houses. This person wanted a board that
would control 3 separate events – a “Bang Event”
that happened as soon as someone triggered the
board, a “Show #1” that occurred for a specified
period of time and a “Show #2” that occurred for a
specified period of time that started after Show #1
finished. He also wanted the board to isolate
itself from the triggering event so that it could
not be re-triggered until after the last event had