With the drought in the market right now for the TDR that some folks are using for HID installs on their bikes, I proceeded to get antsy and not want to wait a couple of weeks. So with a few discussions it was build my own and follow the KISS theory. Just a nice little reliable relay that would kick about 8~10 seconds after it receives power. Total cost including relay and base and sales tax, less then a third of the pre-built device alone. Not to mention it doesn't have the actual relay for the lights, my price includes it.
I have seen some small cube relays that had a time delay device built into them, but then that means once the relay dies you have to retrieve another of the same device. So instead I built the delay and mounted it outside a relay base and used a standard relay. You have issues down the road, simply swap the relay (always carry one spare, or buy them anywhere) or simply bypass the relay with a small piece of wire in it's place. This could also bypass the TDRB if it farks out.
The circuit is pretty simple, 2 transistors, 3 resistors, 1 diode and 1 capacitor. Short and sweet shopping list. This could easily handle 300 ma, but a single relay pulls about 110.
Here it is:
The first attempt had some growing pains... not sure what went wrong but probably due to lack of some insulation, it had no delay. It worked fine till I tried to shrink it. Since my fingers and eye sight are not as good as they used to be, it's now a cat-toy.
2nd attempt looks a little prettier and is properly functioning.
Now seal it up with some heat shrink (multipicle pieces) and liquid tape insulator to seal between them. I would have preferred the marine style heat shrink that has the glue inside, but none available.
Attached with a short lead to the standard relay base. (note, the relay on here is for test purposes, the bike relay will be genuine BOSCH (made in Germany)).
That is all there is folks!
Save your money, DIY!
› Site Search for: Alternative TDR (aka DIY TDRB)