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Discussion Starter · #1 ·
Here ya go:




Any thoughts (BB_MIKE ?). I'll post some part #s later, i.e. Radio Shack. I have not put this in my car...yet, but it bench tested fine. You use a micro-size relay and the whole thing can be built into one of those plastic film containers. You splice into the existing wiring.

I'll explain more later, but for now:

Operation: P.S. you have to build (2) of these, one for the driver's side and one for the passenger's side front marker lights.

During daytime (no parking lights on) This makes your corresponding front marker wink in-sync with the blinking of the turn signal filament.

During night-time (parking lights on) The marker light glows steady (just like factory) until the corresponding turnsignal flashes, with each flash of the fron turnsignal, the marker goes OFF, so the two alternate on and off.

Suggestions welcome. [disclaimer]I take no responsibility for the proper operation of this circuit and any problems that might arise. Don't attempt it if you haven't got a clue on electronics.

Have fun
 

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Any thoughts? but of course
how 'bout investing in a Schematic Software program for your PC? I can email you a Circuit Maker program, but it requires the manual for "password checks" Maybe I can get you a manual also.... I'll look into it if you'd like?

Idea: For a mini-relay what is the DC resistance of the coil? If this is pretty small, say 50ohms you may lose a lot of current through that relay coil STRAIGHT to ground barring the emmiter collector drop of ohhh 0.7Volts. Might cause the front light (same Turn signal + post right?) to not be as bright. Maybe a risistor to ground out of the Transistor's emitter? -Just a thought. The switching concept looks sounds to me
I like the copyright thing also.

Are you offering to sell this, or just to give people the know-how to make it?

------------------
Big Block 402, TH400, 3.73 posi,
13.1sec @ 105 MPH (poor 2.1 sixty foot and rookie tuning)
--will be racing at Chevellebration 2001!--
Picture of me roasting the tires and other guy stuff
Video of me staging (smoke of course)

[This message has been edited by BB_Mike (edited 02-21-2001).]
 

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OK, here is my chance to show my ignorance (as a mechanical engineer, I have plenty).
Why not use a normally closed relay spliced into the +12v to the side marker lamp and energize the relay coil with the pulsed +12v for the turn signal. When the marker is turned on, +12v goes thru the closed relay; when the turn signal is pulsed, the relay opens and winks the side marker. When the side marker is not turned on then the relay winks a dead circuit.
 

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If you know the pull-in voltage or current spec of the relay is, you could add a resistor to lower the current thru the coil, but with the transitor rated at 600mA, that shouldn't be a problem(with a 50 ohm coil, the most the collector can ever see is less than 250mA) . If you do add one though, I would just put in in series with the coil, rather in the emitter circuit, as putting one there will lower your base current.
You may need to lower the value of R1 to raise the base current anyway, as you probably would want to make sure the transistor is saturated. Changing it to something in the 250 Ohm range would give you a base current of approx 50 mA, which would turn the Q on pretty hard (right now you're at approx 1 mA of base current, the transistor can handle 200mA of base current).
You may want to rethink the values once you know what the relay pull-in current is. You may be able to go to a lower base current to achieve saturation if your collector current is less, but I don't think you should have any problem supplying the 50mA.
Something else to consider as well: is the flasher unit going to be effected by having this extra current draw on it ( the relay coil and light bulb)? If anything, it will speed up the flash rate, and that can be a problem if it is too fast. I had one flash so fast that the flashers were way too dim just because it was flashing too fast. The indication on the dash looked OK, but outside lights made it look like I had a dead battery. Something to consider if after installing this circiut the same kind of problem is encountered.

[This message has been edited by Gene McGill (edited 02-21-2001).]
 

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<BLOCKQUOTE>quote:</font><HR>Originally posted by JWagner:
When the side marker is not turned on then the relay winks a dead circuit.<HR></BLOCKQUOTE>
This circuit will wink it when the side marker is off, as well.
 

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Discussion Starter · #6 ·
Thanks guys, I really appreciate you taking the time and providing suggestions.

The 10 k is still okay for sufficient base current, although yes, I could turn the transistor on harder--

But, it meets the needs of the micro-sized relay I'm bulding mine with has a 320 ohm coil, so the current draw is not really going to be an issue from what I can tell. If need be, most auto parts stores have the "heavy duty" blinker cans to prevent the "fast blink" that Gene describes. (any more the heavy duty are used generically) Even with the added current, I don't think there'll be any "upsetting" of the system. The 194 wedgie bulb in my markers only draw about 270 mA of current. Just think of the old Impalas with (2) flashing lights in the back for turnsignals. At night, the marker circuit and turnsignal circuit will both aid with current load to the lamp.

If ya think about it, this is basically an electromechanical equivalent to a Digital XOR gate.


JWAGNER,

if I did as you suggests (not putting you down, just explaining) yes, it would flash a "dead circuit", that's not what you want. you want the marker to indicate turning at all times day OR night. During the day time, the relay is off and the marker sees ground, it (the bulb) gets it's +12 directly from the blinking turnsignal circuit. At night, the marker is of course on via the parking light ciruit. The parking light +12 is also used to generate the approx. 1 mA of base current needed to fire the transistor into saturation (or close enough). When the blinker is turned on at night, the +12 now completes the path to the relay coil, since it now has +12 via the turnsignal and ground via the saturated transistor, the coil pulls down the contact robbing the marker of it's only ground connection. This makes it wink alternately with the turnsignal at night.

The idea again is to blink the marker with the corresponding turnsignal REGARDLESS of conditions (parking lights on/off).

I plan on installing these on my '70 come April, by then hopefully the bitter Nebraska winter will have fully passed
 

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Took me back to the 60's.
But I think I cracked some of the code they're using. Sounds like they're putting together some type of hippy van. A Voltswagon that they can chant their ohms in. And they'll drive to all the Greatful Dead shows (They were talking about the Dead circuit) Haven't quite finished it yet, but Blinkers, Flashers, Resistors and Emitters have GOT to be a reference to some type of illicit pills or mushrooms. Just let them keep talking...I'll get it yet.


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Don - Chicago 'Burbs
'67 Malibu Street Machine
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Joe: T hanks for the explanation. I guess that I had sort of unconsciously blown off the idea of have them wink during daylight conditions, as it seems that with bright sunlight the marker lamp might be hard to notice.
Now on to the next great idea: could you replace the relay with another solid state device? Sort of like the solid state flashers.
 
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