to inefficient to jump 12v to 48v?

[jeff262]

as it were i was in the market for some 12v actuators, my local used electronic store has some that are a perfect match but they are 48v, i think they came off hospital beds. they will be used on a lawn tractor with the weak charging system of a briggs engine. just curious if jumping the 12v to 48 will eat to many amps to work
thanks jeff

[vintage1]

Well you might rewind them of course.

You can certainly jump up with a buck regulator or similar, at decent efficiency.

[jeff262]

thanks vintage, i have never delt with a buck regulators, is there on you would recommend?
thanks jeff

[pmackenzie]

A "buck" regulator drops voltage.

If you want to power 48 volt devices from 12 volts you will beed a "boost" regulator.

If you try to power then directly from 12 volts the current will be lower, not higher. The voltage might not even be enough for them to work at all.

What sort of "actuators" are they, and what are you trying to do?

Pat MacKenzie

[vintage1]

I thought a buck regulator was essentially like a car ignition system. Drag current through a coil, switch off and watch it fly.. like a bucking bronco ;-)

Oh. Hmm. Wiki agrees with your naming convention. I'll shut up and get my coat ;)

[pmackenzie]

English is a funny language sometimes.

It is buck as in "opose". (i.e. Bucking a trend)
We also use "bucking" magnets on speakers to reduce the stray fields. At least we used to. Not a problem any more with plasma or LCD TVs.
http://www.madisound.com/catalog/product_info.php?products_id=8285


Pat MacKenzie

[gigelus2k3]

vintage,

That's the operating principle of the boost converter; you need a diode too between the hot end of the inductor and the load's filtering capacitor.

jeff,

The efficiency of converting 12V to 48V this way would be quite good. Just don't forget that the current consumption from the 12V supply will be about 4 times larger than what your actuators eat at 48V.

[jeff262]

i'm not sure how you euros work over there but i just got the specs on the actuator and it says that it is 24V actuator but powering it with my adjustable power supply it doesn't work until it hits 48Vdc, tried a 24v battery also and i got nothing from the actuator. specs say that its swiss and they even measure the force in Newtons. any ideas whay they only work on 48 volts and not the 24 that the specs say?
thanks jeff

[vintage1]

i'm not sure how you euros work over there but i just got the specs on the actuator and it says that it is 24V actuator but powering it with my adjustable power supply it doesn't work until it hits 48Vdc, tried a 24v battery also and i got nothing from the actuator. specs say that its swiss and they even measure the force in Newtons. any ideas whay they only work on 48 volts and not the 24 that the specs say?
thanks jeff

That's why they are/were in the surplus shop?
Rewind em!

[jeffs555]

It would help if you posted a part number or some specs. All we can do without that is just speculate. Is that rating 24V dc or ac?