Hi,

I have deassembled a surveillance camera containing a sharp ccd with
ir3y48a1 and lr38603a chipset. These cameras seem to have been popular
a few years ago, and are still sold as reverse cameras with LCD
monitor in many online shops.

I am looking at the input of the mc34063 voltage regulator mounted at
the same side as the lens itself. (Complete dissassembly). Between the
12V pin on the connector to car battery and the pins 6,7 and 8 is a
fairly large (for SMD) black component with two leads and "100"
printed on the top. It does not look like an SMD capacitor, and
measuring it with an ohmmeter give open loop. There are two other such
components on the board and they measure around 2 ohm, but I do not
know what is in parallel to those two other components. The PCB looks
like it is 4 layers and the traces are not easy to follow.

I try to find out what kind of component this "100" box is.

I have debugged the camera unit up to the video input. If I apply a
composite video signal (those that typically run down yellow wires or
plugs on TV sets) to the video input of the 2.4GHz radio transmitter,
I can see video on the TFT monitor. (This is RF bound signal
transfer). This means that the wireless part of the camera is working.
I measure the voltage out from the video output of the ir3y48a1/
lr38603a combination and the dc-level is 0, and the TFT monitor is
black. (not noisy like RF is when there is no carrier or lock). The
camera seems to have stopped working after a connection to the battery
where the banana clip lost connection. These MC34063 chips seems to
occupy a fairly large percentage of 12V powered car equipment, so they
must be either cheap or reliable or both.

I have not measured on the camera with power on so far as there is a
great chance of slipping with the probes and short circuiting
something else. Currently I am just inspecting and doing simple
resistance measurements on the power lines. I do measure open loop
between pin 6,7 and 8 and 12V so I suspect that "100" thing to have
died.

Besides, I discovered that whoever made that design decided to skip
the Rsc resistor which is mentioned in all datasheets and application
notes between pin 8 and 7. 6,7,8 are shorted by a piece of pcb track
between the pads. Could be that they have placed the Rsc in series
with the voltage input. I found the suggested capacitor between ground
and pin 8.

Now if anybody has experience with these cameras or have a suggestion
to what that "100" thing is, I would be happy to exchange more info.

--
Svenn

Your best option may be to remove one of the other components to evaluate
it's characteristics, if you can.

I recently discovered some similar looking components in an older 8mm
camcorder, but it was conveniently marked CPxx, 2A on the board.
I took this to mean that it's a fusible device with a rating of 2 amps.
These particular components are marked 50 in bright yellow, bold characters
(but I have no idea why 50 represents 2A) .

I haven't seen any of these particular surface mounted components before,
but then I haven't been dealing with very much consumer electronics gear for
a long time.
The last CP components that I was familiar with were TO-92 devices with
leads, and marked N20, N30 etc, IIRC.

If one of the out-of-circuit 100-marked components shows very low
resistance, and no inductance or other characteristics, it could very well
be a circuit protector, but that's just a SWAG.

--
Cheers,
WB
..............


"Svenn Are Bjerkem" wrote in message
...
Hi,

I have deassembled a surveillance camera containing a sharp ccd with
ir3y48a1 and lr38603a chipset. These cameras seem to have been popular
a few years ago, and are still sold as reverse cameras with LCD
monitor in many online shops.

I am looking at the input of the mc34063 voltage regulator mounted at
the same side as the lens itself. (Complete dissassembly). Between the
12V pin on the connector to car battery and the pins 6,7 and 8 is a
fairly large (for SMD) black component with two leads and "100"
printed on the top. It does not look like an SMD capacitor, and
measuring it with an ohmmeter give open loop. There are two other such
components on the board and they measure around 2 ohm, but I do not
know what is in parallel to those two other components. The PCB looks
like it is 4 layers and the traces are not easy to follow.

I try to find out what kind of component this "100" box is.

I have debugged the camera unit up to the video input. If I apply a
composite video signal (those that typically run down yellow wires or
plugs on TV sets) to the video input of the 2.4GHz radio transmitter,
I can see video on the TFT monitor. (This is RF bound signal
transfer). This means that the wireless part of the camera is working.
I measure the voltage out from the video output of the ir3y48a1/
lr38603a combination and the dc-level is 0, and the TFT monitor is
black. (not noisy like RF is when there is no carrier or lock). The
camera seems to have stopped working after a connection to the battery
where the banana clip lost connection. These MC34063 chips seems to
occupy a fairly large percentage of 12V powered car equipment, so they
must be either cheap or reliable or both.

I have not measured on the camera with power on so far as there is a
great chance of slipping with the probes and short circuiting
something else. Currently I am just inspecting and doing simple
resistance measurements on the power lines. I do measure open loop
between pin 6,7 and 8 and 12V so I suspect that "100" thing to have
died.

Besides, I discovered that whoever made that design decided to skip
the Rsc resistor which is mentioned in all datasheets and application
notes between pin 8 and 7. 6,7,8 are shorted by a piece of pcb track
between the pads. Could be that they have placed the Rsc in series
with the voltage input. I found the suggested capacitor between ground
and pin 8.

Now if anybody has experience with these cameras or have a suggestion
to what that "100" thing is, I would be happy to exchange more info.

--
Svenn

On Aug 18, 1:47*am, "Wild_Bill" wrote:
If one of the out-of-circuit 100-marked components shows very low
resistance, and no inductance or other characteristics, it could very well
be a circuit protector, but that's just a SWAG.

With this in mind I consulted a colleague and he suggested it could be
an inductor. He measured the other "100" chips on the camera board and
they all show around 2 ohm dc resistance. Only my little friend show
open loop. A bit of googling brought us to www.chipinductors.co.uk and
we could identify the inductor as being type ecm32t-100, a 10uH
encapsulated inductor with Rdc 2.1ohm and Idc of 150mA, probably a
nice little surge protector side effect. Now I just need to get a new
one somewhere.....

Thanks and kind regards,
--
Svenn

On Mon, 17 Aug 2009 19:47:46 -0400, "Wild_Bill"
put finger to keyboard and composed:

Your best option may be to remove one of the other components to evaluate
it's characteristics, if you can.

I recently discovered some similar looking components in an older 8mm
camcorder, but it was conveniently marked CPxx, 2A on the board.
I took this to mean that it's a fusible device with a rating of 2 amps.
These particular components are marked 50 in bright yellow, bold characters
(but I have no idea why 50 represents 2A) .

CP = (C)ircuit (P)rotector ???

I haven't seen any of these particular surface mounted components before,
but then I haven't been dealing with very much consumer electronics gear for
a long time.
The last CP components that I was familiar with were TO-92 devices with
leads, and marked N20, N30 etc, IIRC.

http://www.datasheetcatalog.org/datasheet/rohm/icp.pdf

ICP-N50 = 2A semiconductor circuit protector

If one of the out-of-circuit 100-marked components shows very low
resistance, and no inductance or other characteristics, it could very well
be a circuit protector, but that's just a SWAG.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

In message
,
Svenn Are Bjerkem writes
I am looking at the input of the mc34063 voltage regulator mounted at
the same side as the lens itself. (Complete dissassembly). Between the
12V pin on the connector to car battery and the pins 6,7 and 8 is a
fairly large (for SMD) black component with two leads and "100"
printed on the top.
It's an inductor.

--
Clint Sharp

Yep, Frank, that they are. Board printing/markings shows CP901 (etc) 2A 72V
for each one in the camcorder, and very few of the other components have any
designations printed on the board(s).
I think the last time I encountered the TO-92 types, they were in VCRs,
which was quite a long time ago.

--
Cheers,
WB
..............


"Franc Zabkar" wrote in message
...
On Mon, 17 Aug 2009 19:47:46 -0400, "Wild_Bill"
put finger to keyboard and composed:


I recently discovered some similar looking components in an older 8mm
camcorder, but it was conveniently marked CPxx, 2A on the board.
I took this to mean that it's a fusible device with a rating of 2 amps.
These particular components are marked 50 in bright yellow, bold
characters
(but I have no idea why 50 represents 2A) .

CP = (C)ircuit (P)rotector ???

http://www.datasheetcatalog.org/datasheet/rohm/icp.pdf

ICP-N50 = 2A semiconductor circuit protector


If one of the out-of-circuit 100-marked components shows very low
resistance, and no inductance or other characteristics, it could very well
be a circuit protector, but that's just a SWAG.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

In article , Franc Zabkar
writes

ICP-N50 = 2A semiconductor circuit protector

I've seen a lot of those in Amstrad equipment.

--
(\__/)
(='.'=) Bunny says Windows 7 is Vi$ta reloaded.
(")_(") http://imgs.xkcd.com/comics/windows_7.png

On Aug 18, 9:05 am, Svenn Are Bjerkem
wrote:
On Aug 18, 1:47 am, "Wild_Bill" wrote:

If one of the out-of-circuit 100-marked components shows very low
resistance, and no inductance or other characteristics, it could very well
be a circuit protector, but that's just a SWAG.

With this in mind I consulted a colleague and he suggested it could be
an inductor. He measured the other "100" chips on the camera board and
they all show around 2 ohm dc resistance. Only my little friend show
open loop. A bit of googling brought us towww.chipinductors.co.ukand
we could identify the inductor as being type ecm32t-100, a 10uH
encapsulated inductor with Rdc 2.1ohm and Idc of 150mA, probably a
nice little surge protector side effect. Now I just need to get a new
one somewhere.....

Scrounged around in repair sets we have in the lab and found a chip
inductor that nearly fits the specifications of the one originally on
the board, and now the camera works again. The ecm32t then really
worked as a protector since the camera survived the "jump start"
voltage level applied to the power. Hope the new one will be as
protective as the old one. Hope I never live to see ....

--
Svenn