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Topic: SOLVED !! internals of the auto lamp module (Read 15327 times) previous topic - next topic

SOLVED !! internals of the auto lamp module

Reply #15 –
I'm using old model train power supply. If you look at this picture once again, you can test it the same way.

First and fourth lead is connected to +, second lead is connected to the ground. the third wire is the relay output (I'm using a test light instead of relay; relay - is connected to the ground) and the last wire is connected to one lead of resistor (aprox 140k) and the second lead of the resistor is connected to ground.

PS: I have two of these modules, but I don't have a car with autolamps. I'm going to modify the silver bird's wiring in the future.
 

SOLVED !! internals of the auto lamp module

Reply #17 –
I've got mine open, and I'm trying to determine where the relay out power comes from, and I'm pretty sure it comes from that transistor that sits right on top of the diode. (Images are clickable so you can see them full size)

SOLVED !! internals of the auto lamp module

Reply #18 –
Yes, Q2 (as you called this transistor) is powering the relay out. Q1 is NPN type and Q2 is PNP. They are working together. The Q1 is just the voltage invertor for Q2.

If you want, I can make a complete schematic of this circuit at the weekend. It's very easy circuit.

PS: As you probably noticed, this circuit has only one safety feature. It's the D3 diode. It protects transistor Q2 agains the voltage peaks during switching the relay. When the D3 diode is gone, the Q2 transistor will say you bye bye too (most probably).

SOLVED !! internals of the auto lamp module

Reply #19 –
the middle solder run is the output power delivery to the relay,,
thank you trinom,, just confirmed that bugger is a PNP as well.


When you said earlier you your readings for the transitors are "from the top"  do you mean from the top as in typical Collector then base then emitter?

SOLVED !! internals of the auto lamp module

Reply #20 –
I still don't quite understand how you tied D3 to protecting q2  but that's fine I'm out here troubleshooting it now I got a little delayed

Are you sure you don't mean D1

SOLVED !! internals of the auto lamp module

Reply #21 –
I think i have q1 and q2 as bad

With module plugged into car headlamps off, auto lamp ckt on  source voltage was approx 12v
**did not do power off readings

IC1  Pin1  5.8v

D1c  12v
D1a  0v
.. resistance readings  pn  ITT  ZY  24
open one way,,  950koms the other way

D2c  5.1v
D2A  0v
.. resistance readings  pn  motorolla 52  31B
15mg one way,,  open the other way

D3c  0v
D3a  .5v
.. resistance readings  pn  ITT  ZY  24
90kohm one way,,  50mg ohm  the other way

D4c  11.1v
D4a  11.9v

D5c  11.2v
D5a  11.8v


**i kinda messed up how i labled the caps,, hope you make sense of this
c1c  3.5v
c1a  5.1v

c2c  .1v
c2a  ?

C3 Big one (i did not lable caps right)
C3c 0v
C3a 5.8v

C4 (next cap going clock wise)
C4c .1v
C4a .5v

q1  c .1v  b .5v  e .1v  part number 48-2
resistance readings 
C-B one way 57kohms  , open the other way
B-E one way open, open the other way
C-E open either way


q2  c .1v  b .1v  e 12v part number 48  .10
resistance readings
C-B  2.1ohms one way,  2.2ohms the other
B-E  open one way, open the other way

SOLVED !! internals of the auto lamp module

Reply #22 –
Keep on with the work guys! I wish to do some work on mine in the future. My auto dimmers don't work properly. I love the auto lamps, but would prefer to do away with the auto dimmers all together if possible. My brights only come on when they want to. Usually when there is on-coming traffic. It's almost as though it is working backwards.

SOLVED !! internals of the auto lamp module

Reply #23 –
double check your wiring on the connector of the auto dimmer switch,, pull down the related paged to the evtm from my or trinoms or foe's links.

pm or call me anytime you want to do some preliminary checks.. 304 772 3411

SOLVED !! internals of the auto lamp module

Reply #24 –
Quote from: jcassity;406532
When you said earlier you your readings for the transitors are "from the top"  do you mean from the top as in typical Collector then base then emitter?
No, I thought reading from top of the board to the bottom. In fact it is pin 1 2 3, but I only read the values. I didn't know which pin is which (BCE or EBC,...), because it's easy to tell from the values later.
 
Quote from: jcassity;406544
I still don't quite understand how you tied D3 to protecting q2  but that's fine I'm out here troubleshooting it now I got a little delayed

Are you sure you don't mean D1
I'm sorry, I messed it up. You are right. D1 is the relay protection and D3 doesn't have connected cathode. Look closely on the board. There is no path from this solder joint. You can throw away this diode. It's just useless weight :D.

SOLVED !! internals of the auto lamp module

Reply #25 –
with those type of transistors, with the flat side to your right and legs pointed down..  they go CBE.

i personally wouldnt be able to tell what leg was what after readings,, i cant determine if it is a common base, common collector or common emitter without doing an etch and sketch of the board to build a diagram.  not sure its safe to assume vcc is always the collector,, but thats why your mr smart!  : ), you got one up on me~!

sorry about the mess up on the capacitors,, i was in such a hurry i didnt lable them right going clock wise and neglected to sort out c3 and c4 correctly.

my biggest challenge is finding a pnp transistor with no electronics supply house around.  i could harvest from old boards,, from stuff i dont throw away.  i have a few transistors just the right size but im pretty certain they are all your common npn.

ok,,,,,,,,
what are your thoughts on my readings?
you agree my q1/2 is bad?
are you saying d1 is a "blocking diode"?  to protect transistors? - if so thats why i see the annode bonded to one of the transistor legs.
do you think a blocking diode on the 'relay output' would protect the board for a spike introduced from the car in the future? (anode to the relay coil side , cathode to the middle board pin)

one other thing,  dont you find the two relays interesting how they are configured on the drawings?  i have asked someone with a little more geek in them than me what this configuration is,, in my minds eye i can only see two relays working off the amplifier middle pin to generate a very very low current ,, sort of a digital high so to speak to trigger the first relay coil.  ,, i dont know,, it kinda makes my head hurt.

SOLVED !! internals of the auto lamp module

Reply #26 –
I've noticed, that both of the transistors have EBC label, look at them closely. Q1E is connected to the ground and Q2E is connected to the battery power. Be carefull in selecting propper PNP transistor. It has to be able to feed the relay. I guess Ic has to be greater than 0,5 A.

Here is the output stage of the module


If you are trying to measure the transistor, don't use ohmmeter mode of your multimeter. It's useless. You should use diode mode.


PS: Transistor as a switch can be used only as a common emitor.



Jay, control the Q1 base voltage first. I think your problem isn't blown transistor.
When the lights are off it should be slightly below 0,5 V. When it's on it should be about 1,2V (I've corrected this value on the table on previous page I've found a typo in the numbers).

SOLVED !! internals of the auto lamp module

Reply #27 –
ohm reading one way and the other still offers the same result for diodes,, transistors are nothing more than two back to back diodes relativly speaking.  Never had a problem using ohmeter in the past, diode check is something i can do... no biggie.Im skeptical though because the two individual transistors regardless of pnp or npn, they should still read fairly alike just the opposite of each other.

I see you did correct q1 base info, thank you.  Now to figure out whats triggering the base of q1b to get that voltage up,, humm it needs .6v to get there so perhaps that accounds for a defective diode somewhere.

if i introduce a static potential on q1b, that may get q2c to produce power out.

based on what you drew above, looks logical to me.

SOLVED !! internals of the auto lamp module

Reply #28 –
D3 diode isn't useless. I missed the path to the chip. It's the key!

D3C: when it's on, it has 5,2V, when it's off, it has 0V.
D3A: on - 1,2 V .... off 0 V

Check the first table, I corrected values for D3. I had to measure wrong pins yesterday .

Triggering signal comes from pin 4 of the IC.

SOLVED !! internals of the auto lamp module

Reply #29 –
What signal voltage level are you getting on pin4 in the on condition