
Re: Wiring 555 Timer as Signal Flasher Honda CT90?
On Aug 29, 11:15 am,
ben...@bennetwilliams.com wrote:
> On Aug 29, 1:23 pm, Gerryo <ger...@telus.net> wrote:
>
>
>
> > Hi Folks:
>
> > I need a bit of help.
> > I want to use a 555 or similar timer to activate my signal lights on
> > my trail bike.
> > Why do I want to change the original system? I have plans to go to all
> > LED signals and brake lights so this circuit board is the first step
> > and the original thermal flasher is not that reliable and does not
> > work well with low current draw of the LED's.
>
> > REQUIREMENTS: I need the circuit board to be a plug in unit so I do
> > not have to modify the bike wiring to be able to use this board. Note:
> > This turn signal circuit is always powered by the ignition Switch and
> > 6VDC 5.5AH battery and I don't want to modify this feature if at all
> > possible..
>
> > ORIGINAL SETUP:The original turn signal circuit used a thermal flasher
> > and did not present a problem as it was in series with the relatively
> > high current indicator bulbs and was not activated until the manual
> > signal switch was in L or R position and it gave the flasher time to
> > heat up and start flashing.
>
> > PROBLEM: The replacement circuit ( see this link -http://gerryo.wordpress.com/2007/08/29/555-relay-switching-circuit/-
> > to the diagram in my blog) works well with the single exception the
> > relay and the 555 are always cycling at a 1 hertz rate even when the
> > signal lights are in the OFF position. This is unecessary use of
> > limited battery power and will wear the components out quickly. Anyone
> > have any ideas how I could modify the circuit to intially cycle the
> > relay for maximum 1 minute when manual L or R is selected,then have
> > the relay and timer turn off until the L or R switch is selected
> > again? Disregard the horizontal line passing through the timer this
> > is a scan error.
>
> > POSSIBLE SOLUTION: I was thinking a 556 dual timer as well as using
> > the Normally Closed position on the relay contacts might be useful in
> > this situation but I am at a loss on how to connect it. Any ideas or
> > advice would be appreciated.
>
> > Cheers...Gerry
>
> I would approach this problem with a "sensing" circuit. Generally,
> you can keep your flashing circuit just like it is. Just sense the
> turn signal switch being switched to L or R with a PNP transistor
> circuit tied to the circuit board output. When the switch is turned
> to either L or R, it ties the circuit board output to ground via the
> turn signal lamps. That could turn on a PNP transistor. The
> transistor circuit can then turn the 555 timer on and off.
>
> Sorry. I don't have the time to design the whole circuit, but
> hopefully this will give you a direction.
>
> BRW
30 August 2007 8:17 PM
Thank-you very much for your replies. It has given me a few avenues to
explore.
Cheers...Gerry