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automotive VU meter style tail lights

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shokjok

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I am experimenting with a shorting rotary switch, a flasher string, a 4PDT relay and LED tail lights in an escalating auto tail light project for my Dodge van. I plan to attach the shorting rotary switch to the brake pedal hinge pin or by a push rod to the shaft. Feed cabling from the relay's common contacts would be inside the longitudinal body and feed the supplemental LED tail lights.
I am expanding on my bike trailer tail light interface project located elsewhere on this site. Unlike that project, the relay coils are fed from the signal switch assembly in the column. I must maintain the current brake light voltage feed, attaching these extra lights above the existing tail lights. I will also use a label on the rear door to advertise this feature. My question is, has anyone had success with this accessory? I am ceding any intellectual property rights to this idea.
 
Search here for "night rider". Many topics come up.
 
I've re-designed my layout after seeing how the brake switch is mounted in my Dodge van. The pedal pin is a collar that mounts between the bracket tabs, with a pin and locking caps holding the pedal arm in place. I am now considering using a sliding potentiometer connected to the booster pushrod by two opposing springs ( similar to a throttle body or carburetor linkage). A National Semi LM339 or LM3914 IC would then be used as an interface driver feeding PNP power transistors. On paper, it looks good. Assembly could be time consuming for this concept.
 
Do you know about these **broken link removed** sorts of position sensors?

The lm3914 could be interfaced easily to optoisolators. High or Low side drivers can also work.
You didn't offer much to work with.

Not exactly sure what your planning, a single light?

When i saw the mention of an LM3914, I was thinking "bar graph". Then I though about turn signals with a bar display.

If it's just a switch, why not an opto sensor. They consist of an emitter and transmitter on a "C" shaped piece. Hall effect is another possibility. You can buy threaded magnets. I used them for a positioning project.
 
I'm skipping out on using the LM3914 IC with optoisolators and output transistors. My sliding brake switch uses two thin wood strips and a fusible link-fed stepped slider, that connects screwed tabs on one strip, feeding the additional tail lights above the original brake lights. A power switch is added to turn off this feature if required. I passed up using a slide switch and diodes, easier on paper than in a circuit.
The overall intent is a large scale rear-mounted VU meter whose light intensity depends upon the applied brake pressure, complemented by a dash-mounted LED array. A schematic and layout is forthcoming to explain my plan in more detail.
 
Here is my planned prototype project for my full-size 1998 Dodge Ram van. The existing tail lights are supplemented by extra tail lights hopefully to reduce collision frequency. One drawback is the flasher pulse width that could keep the upper tail lights dark. A pulse stretcher may have to be added, or several flashers tried for best results. No power switch is added, as unplugging the circuit is more convenient. The 4PDT relays can be subbed with two SPDT relays having parallel-wired coils. The brake slider prototype would be a thin steel plate between two support strips, connected to the slider plate by another link rod, that connects exposed bolt heads to tabbed wires feeding the relays and LED display. Photos will be posted when this circuit is eventually built.
The two blobs were from a pen eraser.
 

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