Article Alternative TDR (aka DIY TDRB)

T_C

Joined
Mar 8, 2012
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Location
St. Louis, MO
Bike
2005 St1300
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8568
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:
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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.
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2nd attempt looks a little prettier and is properly functioning.
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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.
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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)).
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That is all there is folks!
Save your money, DIY!
 

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You know what I love about this site?
We have people that are willing to share and others that actually are able to read and use the above!
(and I really wish I was one of the latter!)
 
+1
Nice that's been on my to do list for a while to feed my acc panel.
How long does it take to bleed down the cap if you cycle the power?
 
It bleeds down enough that you won't get an immediate re-trigger. About a 1/4 a second of power loss and it's 4 seconds before restart. I was toying with the idea of putting a cap across the coil and seeing if I could delay power off.. but that would require a bit more room (fairly good size cap) then I plan on dedicating to this build.

The 2nd generation will be built around a 556 chip and then I might try a delayed off. Half that circuit is designed.

Hey that's not a bad idea you got there.. a short delay for the accessory distribution panel and then another short delay for lights.
T
 
Didn't think it thru but here's some food for thought.
LINK

At one point I had the dumb idea of integrating all the fancy schmanzy stuff using a pic.
The thought being all the switches and pots for the electric gear etc in a pod up front that just uses a few wires to talk to another pic circuit in the tail that does all the switching delays pwm yadda yadda. Sorta like this LINK but with control for the heated gear and time delays, maybe load shedding.



I think blrfl pointed to a ready made gizmo that does just that might even be wireless I forget LOL.
 
Made a discovery last night by accident and it will save me from trying to engineer in the 'delay off' circuit.

I had wanted the 'delay-off' to prevent my HID's from getting warm-restart. Say if I were to accidentally stall the bike or (not that I did this) if I put the bike into gear without raising the kick stand. Well since I didn't do either of those last night on my test ride of the new lights, I discovered that the aux circuit is not interrupted by the starter switch. So, while I wasn't restarting my bike in the driveway, my headlights stayed lit the whole time and no unnecessary power cycles on the bulbs.

Woo-hoo! :hat3:
 
That would make sense. Since you are picking up your switched circuit from some other source, it wouldn't loose power when refiring. The one thing to keep in mind that it is still possible to drop a light temporarily. What can happen is your voltage can drop too low to maintain the circuitry in the ballast. If the voltage dips low enough it may not refire that light when voltage levels return to normal. This is hit and miss and as your battery ages is more likely to happen but will be a rare event either way. Of to course as long as you don't stall or forget the sidestand it won't happen. I just want to mention it as you may discover this issue and if you had the restart consider that a possibility and fully power down everything and refire to see if it corrects the issue. I have had it happen once to me. Since I had my bypass switch I just flipped it manual off and back on.

I still have a failed TDR that I should tear apart to see how it is designed.
 
I'm reminded most days that I'm not the sharpest knife in the drawer, and, seems like, this post is today's reminder: This post will make perfect sense, I'm sure, as soon as I find out: What's TDR, and, What's TDRB? (I did get the DIY part.)
 
I'm reminded most days that I'm not the sharpest knife in the drawer, and, seems like, this post is today's reminder: This post will make perfect sense, I'm sure, as soon as I find out: What's TDR, and, What's TDRB? (I did get the DIY part.)

TDR is Time Delay Relay. Basically the idea is to switch on the bike's ignition but not have the headlights come on right away. With the OEM halogens it isn't a big deal to have them cut out while starting. Xenon HIDs don't like the power getting cycled while they are in warm up mode. So you can change your process by holding the starer button, install a manual switch that can be forgotten to switch back on or in the TDR case install a device or circuitry that starts a timer if you will when the ignition is switched on and automatically turn on the lights after a delay that is long enough to start the bike.

As far as TDRB. I assume this is option B. The original article was using a purchased TDR. It seems that it is taking longer to get these due to more demand and lack in production capacity of the seller. So this article walks one through a simple design of one. When I originally did the TDR article I considered this route but thought the purchased one would be easier for people to do.
 
Actually the B in TDRB stands for base.

The idea was to keep life simple and reliable. Any size of standard relay could be plugged into the base. Or if a a relay is unavailable and/or my time delay electronics die, you could bypass them with a short piece of wire (aka paperclip).

But given the components used and the load they are placed under ... I predict a long happy life and no bypassing in my future.
 
No problem, if you have any more questions, feel free to ask. Always something to learn out there for all of us... and ya never know when someone's idea will spark a new direction for your project to follow
T
 
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