Help needed converting relay circuit to digital

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Thread Starter


Joined Oct 25, 2010

I am a newbie here. I found this site while looking for resources online to complete a project I am working on.

A little background about myself. I have a 2 year tech degree in Industrial Electronics, a stint in the Marines working on black boxes from aircraft and about 18 years experience designing analog railroad signaling systems.

I am working on making a digital turn signal flasher setup for my motorcycle.

I have worked out a relay based system that I believe will work. I have attached a PDF of this concept. Two things are 'problematic' with the relay version. I need the 5 relays on the bottom labeled 'LED 1-5 Relay' to be slow operate & slow release. I need each relay to have a 200ms pickup delay & a 200ms drop out delay for the sequencing to work. I am hoping to work this out in the digital version. Also the timer self canceling circuit is not shown yet. It will be a combination of timing and/or distance traveled. The distance traveled will be obtained from a sensor in the speedometer head.

If some one could help me understand how to convert the 5 relays enclosed in the dashed red area or even just the 'Request Rely' I would be thankful.

I can not come up with a way to get the 'Request Relay' circuit working. (2nd from left on top row). This relay is triggered by the turn signal switch being pushed either way. The turn signal switch then outputs a 12V+ on either the 'Dg' or 'Ch' wires. This 12v+ signal stays there until turn signal switch is canceled. (by pushing in to release switch). Simultaneously the turn signal switch outputs a 12v- pulse on the Y/R wire. This 12v- pulse is momentary and is removed as soon as turn signal switch is released.

These two pulses from the turn signal switch then pick the 'Request Relay'. The 'Request Relay' then closes a circuit through its top contact to complete a 'Hold" circuit through the 'Timer Relay'. The 'Request Relay' stays up until the 'Timer Relay' is picked by the unshown timer circuit or the Turn signal is canceled by the switch by removing the 12V+ signal on the 'Dg' or 'Ch' wires.

The 'Request Relay' then back checks the 'Right Brake Cutout Relay' & the 'Left Brake Cutout Relay'. Assuming brake lights are not on this then starts the cascading pickup of the 'LED 1-5 Relays'. When the 'LED 5 Relay' picks up it 'Pulse Relay' which then starts a cascading release of the 'LED 1-5 Relays. The 'Pulse Relay' will pick and drop after each cycle of the 'LED 1-5 Relays' and will be used to operate the standard front turn signals & dash indicators.

The 'Brake Relay' will light all of the LED's unless a turn signal or the hazards are selected. If a turn signal or hazards are selected the brake light function for the side selected or both sides in case of hazards will be over rode by the 'Right or Left Brake Cutout Relay'

The picking and dropping of 'LED 1-5 Relays' will give me the flasher sequence shown on the far right (only right side detailed). There will be a 2 second cycle time from top to bottom.

Detailing of turn signal operation is shown at upper left.

Detailing of circuit functions is shown on upper right.

The drawing is done in AutoCad 2009 Mech if that would help someone assist me. I could send it to them.




Joined Apr 20, 2004
It happens that this request runs afoul of our automotive guidelines:
2. Any homemade wiring modifications to signal or head lighting, or penetrations through the fiewall are not for discussion. The lighting function is to too critical for non-approved wiring and connectors. Many safety issues are involved. Preventing chafing in wires passing through driver-made holes is impossible to guarantee.
We can't offer assistance with this.
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