Well .. need abit of help here ..
I'm partially completed on my circuit for a dimmer module using Osram dimming ballast and ATI T5HO tubes ..
Specifications of the ballast
100w ballast supportting 2 tubes
0-10v DC sensing voltage to provide dimming (0v=dim 10v = max bright) 0.5mA max
Dimmer list
10 000uF capacitor
1 Mohm resistor (charging time for brightening)
1 Mohm resistor (discharge time for dimming)
1 10v Zener diode to restrict output to 10v
1 LM358 dual opamp
Everything works for now (dawn simulation last anything from 20mins to 3 hours :rollface: )
Problem, since the dimmer uses a 12v load to sense the 0-10v dimmer signal .. it inadvertently charges the circuit up such that when I turn off the circuit, there's a residual 1+v in the circuit ..
(meaning it cannot go completely dim)
how to make the circuit go complete to 0v when the capacitor fully discharges ??
BTW If I bypass the opamp, the same 12v inadvertently charges the capacitor further.. so no dimming.. and putting a diode at that point makes the dimming sensor 'see' nothing(ie no load??) and command a max bright
How do I make the circuit go from 0 to 10v and then back to 0 again without any charging or hangups at 1+v ??
Any help here ??
Attached is the circuit (simple design for simple pple :smokin: )
I'm partially completed on my circuit for a dimmer module using Osram dimming ballast and ATI T5HO tubes ..
Specifications of the ballast
100w ballast supportting 2 tubes
0-10v DC sensing voltage to provide dimming (0v=dim 10v = max bright) 0.5mA max
Dimmer list
10 000uF capacitor
1 Mohm resistor (charging time for brightening)
1 Mohm resistor (discharge time for dimming)
1 10v Zener diode to restrict output to 10v
1 LM358 dual opamp
Everything works for now (dawn simulation last anything from 20mins to 3 hours :rollface: )
Problem, since the dimmer uses a 12v load to sense the 0-10v dimmer signal .. it inadvertently charges the circuit up such that when I turn off the circuit, there's a residual 1+v in the circuit ..
(meaning it cannot go completely dim)
how to make the circuit go complete to 0v when the capacitor fully discharges ??
BTW If I bypass the opamp, the same 12v inadvertently charges the capacitor further.. so no dimming.. and putting a diode at that point makes the dimming sensor 'see' nothing(ie no load??) and command a max bright
How do I make the circuit go from 0 to 10v and then back to 0 again without any charging or hangups at 1+v ??
Any help here ??
Attached is the circuit (simple design for simple pple :smokin: )
