On Sun, 11 May 2014 23:10:51 -0400, micky
wrote:
For the little 1" x 3" transmitter, I bypassed the pushbutton switch so
it's always closed, and in place of the battery, I gave it the rectified
output of the doorbell transformer, but only when someone presses the
outside doorbell button.
Keying the power to the transmitter might have a side effect. My
guess is that the processor in the transmitter is taking its time
getting itself initialized and making sure all the internal
housekeeping is done before allowing it to belch RF. Such processors
also have a feature that will delay initial transmission so that the
transmitter will not spew junk when powered up. You may also be
charging a few capacitors on power up. I suggest you use it in the
manner originally specified by the manufacturer. Apply the power
continuously, probably with a battery, and key the pushbutton switch
with a relay.
Even so, you might have a slight delay caused by the time necessary to
decode the (rolling code) data. I once built a remote bird trap
release using various wireless remote controls. Timing had to be
quick and perfect to avoid injuring the bird.
I started with a wireless doorbell, which had a built in 1-2 second
delay. A spectrum analyzer showed me that the RF was appearing
instantly. A scope showed that the delay was built into the logic and
was not going to disappear. Next, I tried two different remote
controls purchased on eBay. They were somewhat better, but still had
about a 500 msec delay. I finally had to make my own two tone analog
encoder and decoder, in order to get 100-150 msec response time.
If this is the type of hardware you're using, I think the best bet
would be to insert a one-shot circuit (or relay delay if you want to
be crude), that produces a 2-3 second output pulse, for a very short
input pulse from the push button. That will insure that any length
depression of the pushbutton will produce at least a 2-3 second
output.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558