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Power adaptor don't work

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Offline Pier

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Power adaptor don't work
« on: 20 / September / 2011, 17:03:12 »
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Hi,
I have read all posts in Hotwire! Hardware Mods, Accessories and Insights about external Power
adaptors,and don't understood why my new Canon SX130IX can't work with external Power adapter.
I build my own with LM317T. Vout is regulated between 2.9v and 3.3v, but no reaction
from Camera.This voltage is connected to external Jack.Center pin +, Outside negative.
With battery in and out of the Camera same effect -No Power ON !
I tested the adapter with 6 Om Rezistor.It draw 0.5 A and Output voltage is very stable.
With batery the curent when switching On the Camera is 0.35A (350 Ma) if the display lit, without
display the curent is 0.170 A (170 Ma ).
Without this external plug and battery in the Camera - all is OK.
Where is buryed the Dog ?
What are these "Wood" and Dummy battery discused in the posts ? Must they be in the Camera, and why ?
Any wires inside the wood  ?
The power supply for Canon SX130IS is 2x1.5 V AA, or 2x1.2-1.4 V NiMh.
Thanks in advance and forgive my poor english.
Help please.I won't experiment any longer...

« Last Edit: 20 / September / 2011, 17:09:23 by Pier »

Re: Power adaptor don't work
« Reply #1 on: 20 / September / 2011, 19:39:26 »
This voltage is connected to external Jack.Center pin +, Outside negative.
I don't have an SX130 but I want to ask - how do you know this is the right polarity ?

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With battery in and out of the Camera same effect -No Power ON !
Do you have the battery door fully closed when doing these test ?

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What are these "Wood" and Dummy battery discused in the posts ? Must they be in the Camera, and why ?
Any wires inside the wood  ?

Many Canon cameras do not have an external power input jack (the SX130 does).  So people make external power supply adapters by fabricating dummy inserts the size and shape of the camera batteries (sometimes out of wood) and wiring the external voltage source through them so that they look like real batteries to the camera.

Ported :   A1200    SD940   G10    Powershot N    G16

Re: Power adaptor don't work
« Reply #2 on: 21 / September / 2011, 00:03:14 »
http://photography-on-the.net/forum/archive/index.php/t-258510.html
http://www.nextag.com/Canon-ACK-800-Power-4241775/specs-html

The LM317 is rated for 1.2 to 37 volts at 1.5amps maximum current.
Without a circuit diagram it is impossible to diagnose your situation.
It sounds like the regulator is shutting down under load.
Did you bolt a heat sink to the regulator? 
What are the voltage output and the current rating of your transformer?

Re: Power adaptor don't work
« Reply #3 on: 21 / September / 2011, 00:27:15 »
The LM317 is rated for 1.2 to 37 volts at 1.5amps maximum current.
Without a circuit diagram it is impossible to diagnose your situation.
It sounds like the regulator is shutting down under load.

Well, he said he tested with a load to prove that he gets at least 0.5 amps at 3V.  And he tested that the camera only draws 0.35 amps max.   So his circuit and heat sink should be just fine ?

Ported :   A1200    SD940   G10    Powershot N    G16


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Offline Pier

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Re: Power adaptor don't work
« Reply #4 on: 21 / September / 2011, 01:37:29 »
-Thanks for explanation about the dummy and wood battery -now I understood.
-I'm sure that this is right polarity for Canon cameras.In previous post this was discused for some Canon cameras - BUT WHO NOW ?
  I tested it before pluging the adaptor.After the plug of the Adaptor is plugged in, it with his
outside surface disconnect the minus pole of the battery (and vice-versa), via small metal
lamella inside the jack...seems the Camera accept minus this way and disconnect the battery.
 But,the strange thing is center pin. It is always connected to the positive pole(+) of  the battery via 1 Kom (in both directon with the Ohmmeter).
-Yes, the battery door was closed.I won't try revese polarity ! But once this happened with battery, for a while ...1-2 seconds....  Camera still working O.K.
-The output voltage and curent are OK, nothing happens when I press On button.
So, thanks for try to help me.I'll continue to search solution.Canon recommend ACK 800 AC adapter.I don't know what output voltage is there..maybe 3.5 or a little more camera to start.Will see..
« Last Edit: 21 / September / 2011, 01:39:33 by Pier »

Re: Power adaptor don't work
« Reply #5 on: 21 / September / 2011, 02:10:42 »
Canon does not disclose the current draw for its cameras. According to a number of statements made on various forums the current draw using the camera zoom can go as high as 800ma. Most genuine Canon power supplies I have seen advertised state 1.5 amp current rating.

If the power supply is working on the bench and not in the camera, the only logical solution is that either the power supply is not outputting enough current to drive the camera motor and electronics or the polarity is wrong. According to http://photography-on-the.net/forum/archive/index.php/t-258510.html the positive is the centre pin. Therefore; the polarisation used is correct.

If the power supply was built using the correct transformer and regulator, the only logical reason the power supply will not power the camera is either regulator shutdown due to lack of adequate regulator heat sinking or the power transformer cannot deliver enough current to fully power the camera.

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Offline Pier

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Re: Power adaptor don't work
« Reply #6 on: 21 / September / 2011, 02:51:02 »
thepanoguy
Thanks for the answer.After I saw your last post,I made quick test.
The cable with the plug was connected to my stabilized Power supply 1.5 to 24 V/ 8 A max.
And I check the output with oscoloscope - Absolutely clear output voltage 3.15 v !
I gently adjust output voltage to meet 3.15 Volts and same result -NOTHING HAPPENS WHEN I PRESS ON BUTTON .
I'm going to think,I bought defective camera from the store...??
If not -all this is very strange.Maybe this voltage via the jack must be higher than 3.15, but how much ??
10x again.

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Offline Pauls9

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Re: Power adaptor don't work
« Reply #7 on: 21 / September / 2011, 04:08:06 »
Just a random thought: There's quite a variation in the dimensions of power plugs and sockets. Is it possible that the centre hole in your plug is too large to make contact with the pin?

As I say, just a random thought, since everything else seems OK. Although your 1kOhm between the power socket and the battery seems a little odd.


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Offline Pier

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Re: Power adaptor don't work
« Reply #8 on: 21 / September / 2011, 05:20:54 »
Pauls9 ,
No, the contact is sure.I cheked this.I bought the plug with micrometer in the hand.Inner diameter of the jack is 2.5 mm -same outside diameter have my plug.Both contacts with the plug and cable are cheked several times and 100% sure.
Mistery...with this 1kohm seems something is wrong.
Solution is to go to dummy...  wood battery.Thanks Canon !
I use Canon cameras and will continue becouse of CHDK.Thanks to all made this Gift CHDK for us !

Re: Power adaptor don't work
« Reply #9 on: 21 / September / 2011, 06:21:00 »
Another thing to look at. Maybe the voltage in is too low. Find out what the maximum input voltage the camera will take. Sometimes it is 5 volts. External power supplies work on the principle that it requires a higher external voltage to shut-down the internal power others just open circuit an internal power rail switch when the power connector is inserted.

You should not use a resistor in series with the positive rail. Direct + to + and - to -. The regulator will take care of the voltage and current limiting.   

 

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