Re: Alarm system transformer + power supply (would both go bad at once?)

Alarm system transformer + power supply

> (would both go bad at once?) > NO

I'm not sure what to make of these measurements:

  1. Battery hooked to power supply is 12.87VDC:
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  1. Yet, battery hooked to PWR and GND blades of power supply = 0VDC:
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  2. Battery hooked to just GND blade on the power supply = 12.87VDC:
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  1. Battery hooked to just PWR blade of power supply = OVDC:
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This makes no sense to me; but I'm not an EE.

Does this (repeatable) information above tell us anything about the power supply or battery?

Note: This dent in the capacitor was due to it being pressed down against the transistor (I pushed it away):

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Reply to
Danny D'Amico
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What are the voltage measurements of the pins by the capacitor?

What connects to this connector?

What connects to J1 and J2 (GND and PWR post, respectively)?

That black object between J1 and J2 is a relay. This relay needs to be activated by something, and I am guessing a power failure deactivates this relay, enabling the battery back-up.

So, are J1 and J2 inputs with the connector being the output, or vice versa?

Reply to
Nightcrawler®

Are you asking me to check the DC voltage across the capacitor of the D135A low-battery disconnect circuit?

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Specifically these two points, where I had previously measured the resistance (with no power to the circuit) across that same cap?

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J1 on the D135A board goes to gnd on the Radionics D2212B board. J2 on the D135A board goes to pwr on the Radionics D2212B board.

I do not know the answer. Here's a closeup of that relay:

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All I know, for sure, that's bad is that the ELK-TRG1640 transformer has a blown secondary (open circuit) but I don't know what blew it:

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I think the D135A low-battery disconnect is supposed to be taped to the battery, which turns off the circuit at 9.5V but otherwise does nothing else; so that's why I think it's weird that I get

0 volts across J1 and J2 when the battery is hooked up.

To see if it was the battery, I charged the battery on a car charger (6 amp limited) and I was surprised to see the battery only took about 30 ma (I had to measure it since it was too low for the car charger gauge to show any movement).

After five minutes, I took it off, and the battery measured at

13.5 volts (some of which might be surface charge):

Then, I hooked that battery to the D135A and measured across J1 and J2 again (which seems to be the 12VDC input to the alarm circuit board).

  1. The voltage across the battery inputs was 13.31VDC:
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  2. The voltage across the PWR and GND (J2 & J1) spaces was 0V:
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  3. The voltage across the battery & the GND (J1) was 13.31 VDC:
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  4. But the voltage across the battery & the PWR (J2) was 0 VDC:
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I don't understand that.

  1. The voltage across the electrolytic capacitor was 0V:
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  2. And, the capacitor leads appear to have heated up at one point:
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So, could it be that the 16.VAC transformer opened up a secondary when the battery protection circuit opened up a capacitor?

Seems unlikely, doesn't it? Especially just from turning off the main breaker with the generator kicking in the day before?

Reply to
Danny D'Amico

Dud, it looks to me like you got a bad module.. the Cap is bad just to look at, and since you need the relay to close to pass the voltage to the terminals, anything in that hold-in circuit that?s bad will disable that.. discard the module, if you still need a low voltage disconnect feature, try

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the Elk 965 will disconnect the power when voltage drops below its threshold ..

rts

Are you asking me to check the DC voltage across the capacitor of the D135A low-battery disconnect circuit?

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Specifically these two points, where I had previously measured the resistance (with no power to the circuit) across that same cap?

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J1 on the D135A board goes to gnd on the Radionics D2212B board. J2 on the D135A board goes to pwr on the Radionics D2212B board.

I do not know the answer. Here's a closeup of that relay:

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All I know, for sure, that's bad is that the ELK-TRG1640 transformer has a blown secondary (open circuit) but I don't know what blew it:

formatting link

I think the D135A low-battery disconnect is supposed to be taped to the battery, which turns off the circuit at 9.5V but otherwise does nothing else; so that's why I think it's weird that I get

0 volts across J1 and J2 when the battery is hooked up.

To see if it was the battery, I charged the battery on a car charger (6 amp limited) and I was surprised to see the battery only took about 30 ma (I had to measure it since it was too low for the car charger gauge to show any movement).

After five minutes, I took it off, and the battery measured at

13.5 volts (some of which might be surface charge):

Then, I hooked that battery to the D135A and measured across J1 and J2 again (which seems to be the 12VDC input to the alarm circuit board).

  1. The voltage across the battery inputs was 13.31VDC:
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  2. The voltage across the PWR and GND (J2 & J1) spaces was 0V:
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  3. The voltage across the battery & the GND (J1) was 13.31 VDC:
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  4. But the voltage across the battery & the PWR (J2) was 0 VDC:
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I don't understand that.

  1. The voltage across the electrolytic capacitor was 0V:
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  2. And, the capacitor leads appear to have heated up at one point:
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So, could it be that the 16.VAC transformer opened up a secondary when the battery protection circuit opened up a capacitor?

Seems unlikely, doesn't it? Especially just from turning off the main breaker with the generator kicking in the day before?

Reply to
RTS

Hi, First of all, did you check the battery by hooking up a 12V automotive bulb to really see it is holding good charge at 12V? Secondly remove one leg of diodes and check them, one may be Zener type. do the same with capacitor. Remove any two legs off the circuit and check that transistor. The other K1 is a relay, you can check it same way. Then go to next step which you are trying to do now. First thing first. If you can find a URL for schematic, it'll be lot easier to TS.

No power supply on your work bench? If so you can use it as well. I have a lab. grade power supply with several commonly used voltage o/p. Very handy item to have.

Reply to
Tony Hwang

It seems that all three test bad:

  1. The transformer has an open secondary
  2. The low-voltage protection module has an open cap
  3. The alarm system simply beeps when I plug in 12VDC

I plugged the 13.5V battery, without the ELK TRG1640 ac charger and without the D135A low-voltage-protection board, into the Radionics D2212B alarm system board.

The alarm beeped continuously, without any other indication of working, and the current I measured was 98 ma continuous:

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Can all that really happen simply by shutting off the 200Amp main breaker without also turning off the automatic power generator?

Reply to
Danny D'Amico

Looking at your picture, right above where the transformer leads connect to the terminal strip, there is an electrolytic capacitor right above a small bridge rectifier. I can't quite tell but the capacitor could be swollen and shorted. The 3 terminal voltage regulator is above that capacitor attached to the aluminum plate heat sink. Those are the main components of the AC to DC power supply and if one of them is shorted, that could kill the power transformer. ^_^

TDD

Reply to
The Daring Dufas

That's a very nice find, especially since three things appear to have been blown when I turned the power off without turning off the generator:

  1. The ELK TRG140 16.5V AC transformer secondary windings are now open
  2. The D135A battery-protection board cap is apparently blown
  3. The Radionics D2212B alarm circuit board is apparently malfunctioning

The test of the Radionics board was to hook the battery directly to the power and ground leads. That drew 98ma and the alarm system merely beeped an incessant single beeeeeeeeeeeeeeep for the entire time that I left the battery connected.

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Reply to
Danny D'Amico

There were unused leads for two batteries, so, I suspect there were two batteries in series initially. The battery in there now doesn't look all that old. The equipment was made in the 90s as you surmised.

Reply to
Danny D'Amico

That is the most direct test I could have run, so, following your advice, I took the power and ground leads coming out of the alarm system board and plugged them directly into the battery, which was at 13.5 volts.

The current draw was 98 ma.

But the only thing that happened was the alarm system made a single beeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeep that lasted the entire time that the battery was connected.

I tried this, multiple times, for no longer than the time it took to snap this picture though, as I didn't want to ruin anything further.

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Reply to
Danny D'Amico

I'm surprised you knew *where* the transformer leads entered the board, because I didn't say, so, but I see what you're talking about.

Also, I'm surprised you knew that was a bridge rectifier, because, well, because I didn't - but - looking at it from the side, I can see four uninsulated legs, which indicate it has four leads, one of which is marked "+".

Here is the same picture, but, with a few things marked that I know of (including the electrolytic capacitor I think you're talking about):

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I looked and touched and that cap seems OK visually; but, of course, it's probably 20 years old...

For the first time, I'm wondering if it's not just a new transformer, but, that I probably need to replace the entire board...

Reply to
Danny D'Amico

You could try

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for a used replacement board, bearing in mind that any used replacement board is likely to be close to the same age as yours.

I would tend to upgrade to a current system.

Doug

Reply to
doug

It's more likely that there were problems, and the situation wouldn't let it start working again.

Reply to
Michael A. Terrell

Any recommendations, given my goal would be to use all the existing equipment except the board itself and the power supply?

Reply to
Danny D'Amico

Yeah. I've blown the 'bar' inside for the 10A fuse (my fault) and, I've had to replace the disc-shaped battery once (or twice?) but mine has to be from the early or mid 80s and it's still going strong.

It's strange that all three things are bad:

  1. The power transformer secondary blew open
  2. The battery-tender capacitor overheated
  3. The main circuit board isn't working

I wonder what my options are ...

Reply to
Danny D'Amico

That's probably what I'm going to have to do.

Meanwhile, ELK called me back and explained the "limited" part of the "lifetime warranty" on the AC transformer. The service technician said mine has a PTC fuse in the secondary.

He said ELK will replace it for free as long as it was used within the specifications of the device, e.g., in an approved alarm system (which it was).

They told me I could send it to them, or, I could contact these local "trade distributors" to see if they would work with a homeowner:

  1. Home Tech Solution 408-257-4406
  2. Custom Electronics Supply 408-452-8300
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    800-762-7846

So, at the very least, I'll get the transformer replaced, under warranty, by one of those four. Also, I'll ask all of them how much they sell the board I need.

BTW, must I get the exact same board? Or can *any* alarm system board suffice?

Reply to
Danny D'Amico

You will need keypads to match the replacement board, the sensors should be OK although you may have to change the EOL resistors (if they are used).

If you have any 2 wire smoke detectors you may have to check compatibility with the new panel.

Doug

Reply to
doug

I do have smoke alarms but don't know how they're wired.

Likewise, I have motion detectors and mostly hard-wired door/window switches, but some are wireless (the repair ones mostly).

I called a few outfits today looking for the D2212B(LT) control board:

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Apparently Bosch (who bought Radionics) won't sell to a consumer, so I'll need to get the D2212B board from either a distributor or dealer.

They retail about $100 to $125 but they're almost all out of stock on the web pages that I've found them listed.

If I buy a new board that is not the D2212B, am I to conclude I *must* go with Bosch/Radionics since I do have wireless devices?

Reply to
Danny D'Amico

Replacing the alarm panel is fine by me, but, I spoke to someone at Bosch who said that the "frequencies are different" for each manufacturer.

Is that true?

Seems to me that an alarm system as a simple job. If the switch is open, ring the alarm.

Why wouldn't the wired and wireless alarm devices on the doors and windows be compatible with *any* manufacturer?

Is it true that only a Bosch/Radionics panel will work with Bosch/Radionics controllers and Bosch/Radionics switches and motion and smoke detectors?

Reply to
Danny D'Amico

You're not kidding!

I called Bosch/Radionics at 800-538-5807 who told me they have plenty of D2212B(LT) boards in stock (the LT, they told me, simply means it comes without the external transformer in the kit).

But they can't sell them to me. They told me to go to Anixer or ADI.

So, I call Anixer at 925-469-8500, who says they can't sell the board to me, due to their legal agreements. I have to get it from a contractor as a "pass-through" (whatever that means).

So, this seems to be the path of the board: Bosch/Radionics sells it to Anixer who sells it to the pass-through contractor who sells it to me.

I wonder what the markup is each time?

Anyway, now I am looking for a "pass though" contractor, whatever that means. I mean, I realize it's an "installer"; but, I don't want an installer. I want a pass-through guy to just send me the board.

What do I google for? (The Anixer guys couldn't tell me.)

Now for the ADI guys ... 800.233.6261 ... ... they won't sell it to me either. I need a contractor's license. Sheesh.

It's getting to be harder to get a stinkin' alarm system replacement board than it was to get garage door torsion springs! :)

Does anyone know how I can find a "pass through" contractor?

Reply to
Danny D'Amico

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