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Topic: SOLVED !! internals of the auto lamp module (Read 15246 times) previous topic - next topic

SOLVED !! internals of the auto lamp module

Reply #45
how did you determin your transistor part numbers?

thats also helpful to find replacements.

do you think my chip set is bad?

SOLVED !! internals of the auto lamp module

Reply #46
No, Vdd is power + and Vss is ground.

I've chosen the transistors just to match the type. It's not necessary to use exact type in simulation if the transistors are used as switches.

Voltages on the pins are correct, all NOR gates work properly.

SOLVED !! internals of the auto lamp module

Reply #47
ran out to a parts store , no luck finding a quad nor chip set.

SOLVED !! internals of the auto lamp module

Reply #48
Your chipset works well. I will do the simulation for the rest of the circuit in the evening (local time). Check the resistivity of R2 and if it's too different set it to 3k5 or so.

SOLVED !! internals of the auto lamp module

Reply #49
Ill try that, may have to parallel a couple combinations to get it callibrated.

I did buy the transistors you listed on the diagram "thinking" you cross referenced the original one to these part numbers.

I will remove and re-install the original transitors then work on R2, i can see how this resistor being such a low value could effect the q2 output now that i see how you have it laid out.

SOLVED !! internals of the auto lamp module

Reply #50
WHy are you saying to mess with r2?  thats a time delay adjustment to make the auto lamp trigger earlier or later.
I dialed that to the min and max mark while powered up and had no auto lamps.

SOLVED !! internals of the auto lamp module

Reply #51
are you talking about the resistor thats off the collector of Q2?

SOLVED !! internals of the auto lamp module

Reply #52
No, I'm talking about R2, the pot at the lower left corner of PCB. Set it to 3.5k and wait. It take some time to turn on or off (up to half a minute). The next thing, please measure the voltage on the big rectangle testpoint under C1 and C2. This may be the key for the next move.

SOLVED !! internals of the auto lamp module

Reply #53
ok,,
so you have said you dont think the following is bad on my board

q1 or q2
the chipset

since you dont think these are bad, what could be the faulty part?

do you suggest i swap in the transistor part numbers you have on your simulator?

at this point, evey reading i have provided has not yielded any probable fault thus far yet the board is not working.

SOLVED !! internals of the auto lamp module

Reply #54
Please measure the voltage on the big rectangle testpoint under C1 and C2. This may be the key for the next move.

As I mentioned, I used some pnp and npn transistor for the simulation, since I didn't need to take care about the load. I wanted to know, how exactly the end stage works and it gave me the numbers, which are very close to reality.

SOLVED !! internals of the auto lamp module

Reply #55
ok
give me a moment
i will re-install the original transistors and report in about 15min.

i did adjust R2 again , will repeat with original transistors.

will supply voltage readings on the area where the two caps meet on c1&2

SOLVED !! internals of the auto lamp module

Reply #56
Yes, that's it. The voltage should be changing with light intensity. Slowly.


PS: The resistor numbers in the simulations are not the same numbers as we used R1 (sim) = R6 and R2 (sim) = R3.

SOLVED !! internals of the auto lamp module

Reply #57
2.5 V with full light from my garage. .3 V with complete darkness on the point you have shown

SOLVED !! internals of the auto lamp module

Reply #58
This is with the old transistors back on the board

SOLVED !! internals of the auto lamp module

Reply #59
while i waited, i swapped out all the smaller diodes with no luck.

you would think this would be easy, the boards are not using calibrateable resistors so our readings should be consistent. This is starting to become a tad frustrating , especially not knowing what these two transistors are even though you said they are good on my board.

they are

48-2
and
48.10