RF Switch

[Smitty]

I purchased an RF Switch similar to the type sold at Radio Shack where you use a keychain transmitter with an ON button and a separate OFF button. The receiver module plugs into an electrical outlet and then you plug your appliance into the receiver. I would like to modify the transmitter or receiver so that when I push the ON button, it will turn the appliance on for a split second (1/10th second more or less) and then turn it off. Alternatively, I could make the transmitter ON switch momentary so that I push the button for a split second to turn on the appliance. Any ideas on how to do this modifcation?<p>Smitty

[MrAl]

Hi Smitty,<p>What is the longest period you could tolerate
for the appliance to be turned on, like, is
one full second too long or not?

[Smitty]

Hi MrAl, <p>Thanks for your reply. One second would be too long. I believe 1/2 second would be okay but maybe even less.<p>Smitty

[Chris Smith]

I would replace the solid state triac [output] with a 120 volt NON latching relay. When the signal comes on to turn on the triac, it goes to a relay instead which isn't designed to latch, and thus the minute the signal lets go [trigger signal from your hand transmitter] the circuit or relay fails turning it off. You may need to attach a SCR instead of the Triac as a amplifier or load carrier to the relay.

You may include a small cap at the relay coil to hold the cycle for more than the 1/60 of a second to perhaps a full second give or take what you want. This charged cap hold the relay coil on while it discharges. The size of the cap is the time delay.

In other words the SCR allows a higher current signal to flow to the relay coil, where the circuits regular signal to a Triac gate is too small? Also if the signal to the original triac gate is a latched condition signal, it will be a AC signal.

Placing a polarized cap directly in line [series] with a single diode to the gate will turn on the scr until the cap fills up and then the scr will shut off.