no turn signals

Hello everyone  I have seen similar, but not what I am looking for I am building a motorcycle Turn signal switch system for my friends bike. He is building it from scratch in a rat rod theme. I'm  fairly handy with my hands and did fairly well in electronics class in school, which was many, many years ago. So this is my question: I am using a momentary switch attached the the left handle bar, to activate the left and right turn signals. Press toggle to left once to activate the left turn signal and once again to the left to cancel it. Same for the right side but by pressing to the right of course. When the left or right signal is activated and I forget to cancel it, I would like for it to cancel automatically. It's 1975 Honda cb500twin, DC 12 volts and needs to be small enough to fit under the seat. My method includes 8 relays and 2 diodes but still not sure how to cancel each other out. I am using aftermarket LED lights which are replacements for the original lights and I will be using a turn signal flasher unit which will be the correct one to use for these LED lights off of a 2004 Suzuki gsxR 750 or 90's ish Kawasaki zx7 I would very much like for everything to be kept fairly small and light as it is for a motorcycle. As I said I have a method but it's very big and bulky and still can't figure out how to cancel each other out. The switch itself will be on the handle bar and there clearly no room for anything else, so the rest of this turn signal system would have to be places under the seat. I don't think I would need a heat sink, since its not high voltage or constantly powered. Any ideas or diagrams would be very much appreciated  Thank you very much for your help

I'd be tempted to use a PIC(AXE) - a small & cheap programmable chip. IMO relays get to complicated for this sort of thing whereas something programmable can even cancel after a distance (proportional to speed). Otherwise other electrics - flip-flops are probably best suited (ie, T-types (Toggle) which are usually made from RS flip flops (or was it from JK flip flops). A dual package flip-flop might be all that is needed (with a few diodes etc, and 2 relays).

The thing about having them cancel will need some kind of speed sense input. If you turn the blinker on while sitting at a traffic light, you do not want it to cancel on you after the predetermined time. You will have to have some way to determine that the bike is moving and cancel only if it is moving.

My old Yamaha RD CD (that's in Roman numerals - ie, RD400) had self cancelers - left or right, center-push for off else distance controlled off. AFAIK, it was simply distance and not speed related. But with a uPC or PIC etc, speed-related distance is not difficult; it is simply counting distance pulses and dividing by a fixed time to get the speed (relative speed only - calibration for readout isn't necessary). And since uPCs & PICs have a timebase, that should be taken care of, but otherwise a timer could be added.     The pulsed distance would be from an electronic speedo else a reed switch mounted close to the mechanical speedo's rotating magnetic vane - assuming the speedo isn't sealed.    AFAIK timed turn-offs aren't used as they could turn off unintentionally whilst waiting to turn, though a movement sensor (eg, a few distance pulses) could reset the timer back to its full delay. Else a "flashing" buzzer could be enabled after the time delay instead to prompt for manual cancelling. (Why people use fancy circuits for indicator annunciators beats me - it's merely a non-polarised buzzer connected between left & right sides, else a grounded buzzer with diodes to each side - that latter with a MOSFET if all indicators are LEDs (though the diodes could be omitted with the right design, but mere small-signal diodes make it simpler.) Sure, PICs take a bit of learning, but I would use that rather than a plethora of relays. Failing that, some "discrete" electronics (meaning discrete chips as opposed to all discrete components.) PICs can be reprogrammed, modified and extended for more features or better behavior as time progresses - eg, the speed-distance relationship. Admittedly I have avoided PICs for years (decades!), but I intend to break the ice to enable countless "simple" PIC projects that are otherwise complex or time consuming - eg, timed PWM dimmers for dome & puddle lights (irrespective of bulb & LED combinations), various "truth table" circuits (if that..., then do... unless... or do... if... and kill after distance if speed is... etc. Though many such circuits can be made with component combinations, the mere ability to program a PIC and add the input & output circuitry (which is required anyhow) is much faster. And reconfiguration or addition is a mere reprogramming instead of resoldering links or adding new chips etc. But that's after biting the bullet and having a few standard PIC boards. PICs (or PICAXEs) start with 8-pin chips capable up to ~100 lines of code. Bigger PICs can be 28 & 40 pins capable or thousands of lines of code. Most have counters, PWM outputs, etc. And there are many public domain projects on the web. (I ended up with a $35 Arduino Dualimov which is a full blown uPC (ATmega 326) with USB interface, but that was cheaper than big PIC kits, plus I've previously coded for uPCs - but Arduino is an open &public domain platform with lots of program and build examples.)

Could you use the brake light to prevent the turn signal from timing out? IE if the turn signal is on and the brake is off for 30 seconds the turn signal shuts off automatically? Using a discreet brake light input would be much simpler then trying to reference a speed signal.Kevin Pierson

Sorry, should have been more specific. The only time I would want to lights to cancel automatically, would be if I pressed the toggle switch in the opposite direction in order to turn on the other sides turn signal. Other than that, I would like it to stay on till I use the toggle to cancel. I don't need hazard lights. Compact, weight and simple are my number 1 goals Thanks

Why not use an On-Off-On non momentary switch.  Left to turn it on, then center it to turn it off.  12 Volts through a Solid State flasher, then to the center terminal of the switch.  One terminal to the left lamps, other terminal to the right lamps.  Done, no relays needed.

That is nice and is almost exactly what I want. But I would like to use a monetary on-off-on switch. It's just one less thing to worry about when riding, considering that we might be going to a suicide shift on the left side. I don't want the signals to cancel themselves at all, I want it to only to cancel when I choose or I choose the other side turn signal. I never thought it would be this hard to figure out how to make this monetary switch work. I just want the signal to turn on when I press one side and stay on till I press that same momentary switch to the same side and if I press the switch to the other side, only to start the opposite turn signal only, and to turn that new side off I would just press the switch to that new side in order to cancel. Thank you very much for your help

Use latching relays between the momentary switch and the flasher.

Yes latching relays are what I had in mind but, to my knowledge that would require 8 relays just to get the signals to function properly, and I still don't know what or how to wire them so that when left signal is on and I press right that only the right turns on and not both. This is for a motorcycle, space is an issue As I can only find 30amp relays, So 8, 30amp relays and the flasher will take away almost all the space under the seat which leAves 0 room for fuse box Thanks