Transformers

[wil]

I have a Dewalt 24v chop saw. The batteries have had it and after checking online, someone have converted his drill to run off a transformer by taking the dud insides out of the battery casing and wiring in a conection to a transformer so he could then slot the battery back into his drill and run it off the mains supply.
I'm thinking of doing the same thing so what I would like to know is, what type of transformer would I need and what would be the specs of it. I was thinking along the lines of 220v ac to 24v dc producing at least 350 watts to overcome the start up power of the saw. I know you can get 220v to 110v & 24v ones for building site work, but they are quite expensive,i there a cheaper alternative out there.

 

[telectrix]

you'd need a 240/24V transformer. then you'd need to convert from ac to dc by using a bridge rectifier and some electrinics to give a nice smooth 24V dc.

 

[Octopus]

Or just but a cheap 240v drill!

 

[davesparks]

You'd need an output greater than 24V from the transformer to allow for the drop in the rectifier circuitry

 

[telectrix]

buy yourself a dewalt drill or some other 24V tool that uses the same pattern batteries.

 

[Besoeker]

You'd need an output greater than 24V from the transformer to allow for the drop in the rectifier circuitry

Single-phase rectified produces DC about 0.9 times the AC less the diode drops so 28-30Vac.
But, frankly, I wouldn't bother.

 

[tazz]

Hmm at 14amp plus transformer, to drive your drill.....cheaper buying a battery

 

[wil]

Thanks Telectrix,
Is there anything on the market that fits the bill as buying a new battery is about £200

 

[ipf]

Welcome, by the way.

 

[Antony1]

Yes we use 230v to 24vdc power supplies in control panels all the time, they have a 5a power rating but you can get bigger, or you can use 3 x 5a power supplies in parallel. The brand we use are Meanwell, they have them on eBay, to connect the outputs in parallel might require a diode though so they don't back feed each other!

 

[Jamzie]

A switch mode supply would cater for both 110 & 230V supplies, should be able to pick one up from flea bay for a reasonable amount. Personally I'd buy a new battery.

 

[Leesparkykent]

Thanks Telectrix,
Is there anything on the market that fits the bill as buying a new battery is about £200

You could buy a replica battery for about £40

 

[shanky887614]

You could buy a replica battery for about £40

or grab a soldering iron and some batteies offline and replace the faulty ones/all of them.

 

[wil]

You could buy a replica battery for about £40

cheers, I looked on line for replica and yes there are indeed batteries going for 35.00 upwards.I might consider it an option but it's still a pain having to keep charging them.

 

[Engineer54]

I must be missing something here....

What's the main reason for having a battery operated drill in the first place, oh yes, so you can take it anywhere, especially in places where there is no power supply available. So converting it to a drill that needs a lead and power supply kinda defeats the whole purpose....

 

[Antony1]

It's for a chop saw and they are not that portable anyway

 

[shanky887614]

why did you buy a battery one iin the first place?

there is always a genny if you need power for it somewhere.

a chopsaw would kill batteries quick

 

[wil]

It's for a chop saw and they are not that portable anyway

thanks for that, it saved me the trouble of explaining it all again

 

[wil]

why did you buy a battery one iin the first place?

there is always a genny if you need power for it somewhere.

a chopsaw would kill batteries quick

I worked on an airbase, they don't allow 240v stuff only battery, but now I'm retired I won't be shifting it about now, and yes you're right it does kill batteries quick so it's anoying having batteries run out halfway through a job. But as the saw cost me £700 I don't fancy chucking it and I know substitute Batts are £40 each, I'd rather spend the money on a transformer if one exists at under £80 (2 Batts min)

 

[Barry White]

Only thing I can think of in your price range is a start n charge 24v battery charger like this NEW 12/24V AUTO CAR BATTERY CHARGER POWER STATION CAR JUMP START VEHICLE VAN | eBay
may come in handy for the car too