I can, and will, make them... As I had already told another member, let me see the cheapest I can get components for, and I will throw a price together..
Give me until this evening, to research pricing (knowing how to do it, and readily carrying the supplies is a different story...)
If anyone would like a break-down of the operation of this circuit, I will paste it here:
The circuit can be explained as follows: When the car door is open, the push to off (PTO) switch of the door is ON and it charges the 22uF capacitor fully.
The opamp is acting as a voltage follower and its output is same as the voltage across the capacitor, which is 12V when the capacitor is fully charged. Due to a high voltage at the output of the IC, the transistor saturates, turning ON the bulb to full brightness, without delay.
Now, when the door is closed, the door switch is pushed in and hence the switch goes OFF. When the switch is OFF, the capacitor starts discharging slowly through VR1 and the 10K resistor and the voltage across it decreases slowly. Therefore the output of IC 741 also decreases gradually, decreasing the base current to the transistor. This produces a slowly decreasing current through the bulb and the bulb fades out and finally OFF, when the capacitor is fully discharged.
After building the circuit, with the PTO switch in ON position (not pushed in) i.e. the car door open(or brake pedal is depressed, adjust the preset VR2 to the required initial brightness of the bulb. Then push the switch in to turn it OFF(or close the door)(or release the brakes) and adjust VR1 for the time to bring the bulb from full brightness to OFF.
I would suggest you set VR1 and VR2 to their maximum values,
for theater lighting.
Just attach to your Brake circuit, instead, and viola!!!
You can bump up your 3055 transistor to one that will handle a higher current draw, in order to make it last a little longer, but mine has been running for 2+ years. Be sure to follow the setting procedure, in order to adjust the initial brightess, and delay..
(TOO long of a delay makes for poor notice to fellow drivers, in stop and go traffic... you let go and it doesn't fade much before you press it again, and they don't get that "flash" of "new" light, so their brain won't process it as having occured... OUCH....
Another note, these kits will come in small black plastic "project boxes", and will be of the utmost ease to install:
One end of the box will have a quick connect termination-style plug (speaker boxes, etc) and will be the input... the other side will have another of the same stile termination, and will be the output..
simply cut the brake lights positive wires, and run the LIGHT-BULB side of the wire to the "output" termination, and the other end of the cut wire (the one that leads to the brake switch) to the "input" termination, so that this box rides in between the two, ALA:
brake switch(or door switch) --- BOX INPUT --- CIRCUIT --- BOX OUTPUT --- brake lights (or dome lights)
I'll post this evening on a set price, and go from there..
Ray
