Pirate 4x4 banner

1 - 15 of 15 Posts

·
Registered
Joined
·
1,170 Posts
Discussion Starter #1
ok what im looking for is a 1.5 ratio dc to dc step up converter. needs to be able to handle 10 amps. ie: 10v in 15v out.

does any one know where to get one or get me a scematic to make one? i can find all sorts of plans etc online to boost it to like 300v-400v but i dont need that much.
 

·
Registered
Joined
·
3,749 Posts
The only way to do that is with a switching power supply. They're not easy to build and typically will be set at voltages, not ratios. What are you trying to do?
 

·
Registered
Joined
·
1,170 Posts
Discussion Starter #3
im trying to bump a 12-14 volt circuit to 18-20 volts, its a 10 amp circuit.
 

·
Registered
Joined
·
905 Posts
The easiest way to do that is to invert it to AC, step up the voltage higher than you want, then rectify back to DC and regulate to your correct values... sounds like a PITA to me.

FYI: Transformers don't work with DC, unless it is pulsed.

What are you trying to accomplish? or run?
 

·
Registered
Joined
·
1,170 Posts
Discussion Starter #5
trying to find a cheeper way around buying a zeta system for the lights. i just figured that it could be done for less than $250.
 

·
Registered
Joined
·
407 Posts
What you want is a DC/DC converter. A number of sites sell them. If you want to build, check out Maxim IC, they have a lot of controler chips for them. I don't know of any offhand with the ratings you asked for.
 

·
Registered
Joined
·
523 Posts
Just a thought, but if you tapped off of the alternator power upstream of the voltage regulator and downstream of the rectifiers couldn't you get a lot higher voltages? Then that voltage could be regulated down (zener diodes) to the voltage you want. Course that would only work with the engine running.

Am I crazy here is there a reason this wouldn't work?

Chad
 

·
Registered
Joined
·
905 Posts
voltage regulators regulate the field current, of the alternator.. not the actual output current. it's a closed loop device. even if you tap in directly at the alternator, it will only have charge system voltage (roughly 14v)
 

·
Registered
Joined
·
523 Posts
OK, that makes sense, I'm kinda electrically dumb. so if you remove the voltage regulator (on an externally regulated alternator to us it as a welder, you basically just send full voltage/current to the field, and it will make up to and over 100V DC?

chad
 

·
Registered
Joined
·
905 Posts
chadl, yes, the welder setups just run full voltage/amperage. That's why you can tune their output with the idle speed.

I hardly think it would be worth mounting an extra alternator just to run some lights.

I will see if I can finger out a simple circuit diagram to do what you want... I'll post it here if I do.
 

·
Registered
Joined
·
1,170 Posts
Discussion Starter #13
kewl . thanks guys.. i think ya gave me enough pointers to make some thing work...
 

·
Registered
Joined
·
3,749 Posts
I think the easiest way would be to buy an AC inverter and build a 18-19V DC power supply. You can get inverters pretty cheap these days, just be sure you get one thats big enough. You will need at least 200 watts, 250 would probably be better. As a bonus, you could also run AC accessories off the inverter when your lights aren't on.
 

·
Registered
Joined
·
214 Posts
I did a google search for 'high voltage alternator' and got a bunch of hits. Here is one http://www.mtmscientific.com/alternator.html that has a 'booklet' for $10 and a kit to replace the winding/diodes on an alternator for $39 to get it to double the voltage. Yeah , I know you said you only wanted to go to 18V. No clue what the 'booklet' has in it and spending $10 for the booklet may be a crap shoot. Maybe some of the other hits might steer you in the right direction for 18V.
 
1 - 15 of 15 Posts
Top