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Dw911 Type 1 Radio/charger.


MrDewalt

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Hi guys.. I just registered and would like some techy help please.

My radio only works on batteries now and not on mains voltage neither does it charge any more. I checked all three fuses and they're fine.

I checked the transformer and it has no ac voltage from the secondary but does have continuity across the secondary side.

I cannot find any markings on the transformer to identify its values.

So I bought a second radio that works and checked the transformer. It's secondary has 13.9 volts ac.

My question is, does anybody no of an after market or equivalent transformer?

Not being able to identify it makes it difficult to know the milliamps etc.

Thanks in advance.

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www.ereplacementparts.com

They have a factory replacement one.

Thanks for the reply. I have seen these and they are on back order!  May 2012 they might be in stock!!

Which is why I need the equivalent transformer from RS or Maplin etc.

Some sites say they have it in stock. When I email for confirmation, they say it's not in stock.  Dewalt have discontinued it and wont supply me with the technical details to buy an alternative/equivalent transformer.

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http://servicenet.dewalt.com/Parts/Detail/44445

This official Dewalt parts site says it will be available 1/26/2012.

But, they might keep extending the date on you.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

http://www.dewalt.com/Find-Service-Center.aspx

Another possibility would be to find a local service center to see if they can get the part.

But, they might be getting their parts from the ServiceNet site above.

(Transformer part # 429790-48)

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http://servicenet.dewalt.com/Parts/Detail/44445

This official Dewalt parts site says it will be available 1/26/2012.

But, they might keep extending the date on you.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

http://www.dewalt.com/Find-Service-Center.aspx

Another possibility would be to find a local service center to see if they can get the part.

But, they might be getting their parts from the ServiceNet site above.

(Transformer part # 429790-48)

Thanks Steven for the info.

I think that part number may be a 120v transformer. I am looking for a 240v. I am in London, England.

To be honest, I think Dewalt are out of order for not allowing the company that supplies them to reveal/stamp/label the transformers with the electronic values or genuine part number!!

Some people do not want to have a Dewalt part number only.

Radioshack (Tandy In England) had a big book of equivalent part numbers by lots of different companies.

Oh well. Life goes on. ::)

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Hi guys.. I just registered and would like some techy help please.

My radio only works on batteries now and not on mains voltage neither does it charge any more. I checked all three fuses and they're fine.

I checked the transformer and it has no ac voltage from the secondary but does have continuity across the secondary side.

I cannot find any markings on the transformer to identify its values.

So I bought a second radio that works and checked the transformer. It's secondary has 13.9 volts ac.

My question is, does anybody no of an after market or equivalent transformer?

Not being able to identify it makes it difficult to know the milliamps etc.

Thanks in advance.

OK you might need to measure the secondary voltage  no load if that possible on the unit that is working! I'm not familiar with the actual radio set but you can approximate the specification for the transformer.

Measure the no load voltage of the secondary. you have 13.9VAC?? Is there only 1 secondary?

What type of transformer is it toroidal  or E and I (i.e.) old school box shaped?

Does the charger section have it's own power supply?

AND A WORD OF WARNING ALL WAYS USE CAUTION WHEN DEALING WITH MAINS VOLTAGE! Sorry but it has to be said.

A picture or 2 might help as well. ;)

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A good majority of the time I don't see transformers marked in consumer devices. It' common, and it's also common enough that part suppliers change even during the life. The Dewalt part number is what you would expect & need.

Next time, since it's a linear power supply pull the data sheet on the 1st voltage regular, assume the transformers a couple of volts or so higher. Really should not matter too much, if your a little under or over the regulator will dissipate anything over as heat and there will be some tolerance in the design for over or under voltages.

You could also use the Dewalt 120v transformer with a 2:1 step-up (very common 120<->240). Also, if your just looking for a cheap & quick fix, cut the secondary leads and feed it using a DC 12V source. Polarity's only important if they used a half-wave rectifier (uncommon). For a full-wave rectifier (very common) it won't care. I paid <$20 for a 40W 12V DC switch-mode power pack which should easily fit in the case.

Since it already run's off batteries I would not expect any dependency on AC (cheap clocks sometimes use the line freq instead of a crystal).

To be honest, I think Dewalt are out of order for not allowing the company that supplies them to reveal/stamp/label the transformers with the electronic values or genuine part number!!

Some people do not want to have a Dewalt part number only.

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Could be the transformer, could be something else..

I checked the transformer and it has no ac voltage from the secondary but does have continuity across the secondary side.

how are you measuring continuity? By resistance or by the beep! Audio sound.

-by the beep! Sound, you will only get a beep on the secondary since it has less resistance than a 240V primary.

-if by ohms, in the primary should be low resistance. while on the 240 you should get high ohms.

It's a possibility that it could be a diode... or a capacitor... capacitors are notorious to fail and then diodes... imo.

Make sure the transformer works first... if it is ok, you can post a picture here of the electronics and I might help you test our components down the line... it takes time though... good luck.

As for the transformer... I would guess any transformer that is around the same size with same amp rating (although you don't know the amp rating it should not be that much... i would guess a 20amp.. or less) and primary plus output rating should work.

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That would be 4,800W.....  Just how big is this thing ;D

As for the transformer... I would guess any transformer that is around the same size with same amp rating (although you don't know the amp rating it should not be that much... i would guess a 20amp.. or less) and primary plus output rating should work.

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That would be 4,800W.....   Just how big is this thing ;D

As for the transformer... I would guess any transformer that is around the same size with same amp rating (although you don't know the amp rating it should not be that much... i would guess a 20amp.. or less) and primary plus output rating should work.

Thanks all for your responses. I will double check the transformers.

It is the square/oblong type, not round Toroidal. Yes, only one secondary (2 wires only).

I checked the secondary with  beep, volts and ohm. nothing....checked the working unit and 13.9 volts ac.

I will take some photos of the board and post them in the week.

I never disconnected either transformer, just plugged the units in and used my fluke.

I'll report back and load some photos. Thanks to all. Martin.

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