I'm building a electric anchor for my boat. I'm using an electric actuator thats rated at 24v to 36v. I need to step up the power. my boat is only 12v. I was going to use a stepup converter. Found one 12v in and 48v out. Is there a way to control the voltage so i can tune it down to 36v. Also would there be a big difference running it 24v verus 36V?

very slowly. You should try this. Connecting your actuator to too low a rated voltage probably wont hurt it.BTW, it would be helpful if you knew how much current (in amperes), and thus how much power (in watts) this actuator uses while it is raising or lowering your anchor. The reason for this is that the cost of power converters tends to scale with the amount of power they can output.

The amount of power used by your actuator is the voltage across it multiplied by the current it draws.

This place:

http://www.powerstream.com/dcdc.htm

actually sells DC-DC converters of various kinds. But like I said before, before shopping for a converter, you kind of need to know how much actual power (in watts) is required for your application.

Since you're doubling voltage, you'll double input current -- if its 24v @ 10 amps (go with the max numbers) , the converter will need 12v @ 20 amps. *those numbers are just made up, look at the REAL numbers to decide.

Steve is correct it will run faster at 36 than 24, unless it has inbuilt controller to have constant speed over the voltage range.