Flashing 12v To Constant

[petef]

I am in the process of building a lighting control for my custom motorcycle. I need to take the flashing 12v from my turn signals and convert to a constant 12v. I know how to do it with the use of a relay, but to save space i want to do it with solid state electronic components.

 

[Bluejets]

Take out relay, replace with mosfet.

You said you don't want a relay so that means solid state relay is out also (ssr) ...????

 

[Gryd3]

I am in the process of building a lighting control for my custom motorcycle. I need to take the flashing 12v from my turn signals and convert to a constant 12v. I know how to do it with the use of a relay, but to save space i want to do it with solid state electronic components.

Most installations include a control input like a lever or button which is 'constant' which goes to a flasher relay to make it flash. It may be easier to grab the line *before* the flasher circuit than to convert the flashing output to a constant state.

What kind of access / control do you have over the electrics on the bike? Do you still want the dash turn-indicator light to blink?

 

[Kiwi]

The flasher unit is in the supply line to the turn switch, so just remove it and join the two wires on it together.
You will now get a constant 12v out of the turn switch for left and right.

 

[Harald Kapp]

Will it be legal to have a constant on turn-signal instead of a flashing one?
Definitely not legal here.

 

[petef]

Most installations include a control input like a lever or button which is 'constant' which goes to a flasher relay to make it flash. It may be easier to grab the line *before* the flasher circuit than to convert the flashing output to a constant state.

What kind of access / control do you have over the electrics on the bike? Do you still want the dash turn-indicator light to blink?

The control is a momentary push button that goes into a factory module, the module will then control the turn off function of the turn signal.

 

[petef]

Will it be legal to have a constant on turn-signal instead of a flashing one?
Definitely not legal here.

there will not be a constant signal will not be visible from any light, it will just control a transistor to shut down the brake light on the side that I want to flash with the turn signal

 

[petef]

The flasher unit is in the supply line to the turn switch, so just remove it and join the two wires on it together.
You will now get a constant 12v out of the turn switch for left and right.

wish it was that easy but this is on a harley

 

[AnalogKid]

Not difficult to do with something called a missing pulse detector, similar to what fan monitors use to detect when a fan has slowed down or stopped based on a tach pulse. The drawback is that the detector must wait for a bit more than one pulse cycle before changing its output back to the "not-pulsing" state, to make sure there aren't any more pulses coming.

What does the output of this circuit drive? How much current must it source or sink? Does it have to turn off quickly or can it turn off gradually, like with a slope of about 1 second?

ak

 

[Alec_t]

it will just control a transistor to shut down the brake light on the side that I want to flash with the turn signal

That too would be illegal in Europe I believe. Is it legal in the US?
Why would you want to do this? Sounds dangerous to me, since if you were stopped, waiting to turn into a side road, with no brake light showing you would be less visible to any motorist coming up behind you .

 

[petef]

Not difficult to do with something called a missing pulse detector, similar to what fan monitors use to detect when a fan has slowed down or stopped based on a tach pulse. The drawback is that the detector must wait for a bit more than one pulse cycle before changing its output back to the "not-pulsing" state, to make sure there aren't any more pulses coming.

What does the output of this circuit drive? How much current must it source or sink? Does it have to turn off quickly or can it turn off gradually, like with a slope of about 1 second?

ak

Im not understanding where the missing pulse detector would come into play. im looking to get a constant output from a flashing input.

 

[petef]

That too would be illegal in Europe I believe. Is it legal in the US?
Why would you want to do this? Sounds dangerous to me, since if you were stopped, waiting to turn into a side road, with no brake light showing you would be less visible to any motorist coming up behind you .

it would be to turn of the brake light on what ever side I had the turn signal on so that the light can flash with the turn signal.

 

[kellys_eye]

If the lights are driven directly from the ECU then it makes the matter a little more complicated but it can still be done by connecting the turn signal voltage to a monostable whose period is set to be longer than the turn signal on/off period.

This is, as mentioned above, a 'missing pulse' detector.

 

[AnalogKid]

Im not understanding where the missing pulse detector would come into play. im looking to get a constant output from a flashing input.

That is how the circuit works. When pulses are happening within the detection time window, the output is in one fixed state. When pulses stop, the output goes to the other state.

Example, 1 Hz turn signal frequency. Detection window set to 1.5 seconds. As long as the circuit gets an input once per second, the output is in one state. If the pulses stop, the output changes state 1.5 seconds after the last pulse. What you do with the two output states is, like, whatever.

ak

 

[petef]

looks like the monostable will work for what I need. i never herd of it being referred to as a "missing pulse" detector.

 

[AnalogKid]

Same as a retriggerable monostable.

ak