Newbe question DC/DC converter project

[Mike Axe]

I would expect this to be easy for most of you but I enjoy making a fool out of myself so much. First of all, allow me to say hello and thank you in advance for your help. My name is Mike and I want to take a forklift battery (80vdc) and make a simple inverter to produce 12vdc output for lights, horn, back-up alarm and other driver interface systems. I am new to this and a simple regulated converter design would be of great help. I can build it from there.

Thank you in advance of any help you can give me.

Mike

 

[Misterbenn]

You're just about in the range of buck converters. You can probably find an off the shelf product to do this, depending on the current you need.

Otherwise a flyback converter can do this.

 

[nelsonic1111]

Yes I can tell you for a fact they do make them I am a forklift mechanic and our 80v linde pallet trucks and our 80v Jungheinrich fork trucks both have voltage transformers one is 80v 700ah - 12v 100w and the other one is. 80v 700ah - 24v 200w price is around $500 each and how they work is changing dc-ac knocking it down to the proper output voltage then rectifying it back to dc voltage but there's many off the shelf options available

 

[dr pepper]

No fool implied here.
A FLT battery is very unforgiving if you make a mistake.
I suggest that you make a tap after 6 cells from - on the battery to get yourself 12v, a insulated croc clip ought to be ok, dont forget a fuse.
You can get 72v lights/horns and back up sounders.

 

[Tony Stewart]

If you dont understand how they work, I suggest buy now and analyze later to get experience. They come in many grades of smart chargers, and converters for resistive or motor loads preferred under $0.50/Watt to $1/W.

Shop around.

 

[nelsonic1111]

Yes the transformers are variable input from 36-80v dc

 

[nelsonic1111]

The only problem you face with tapping 6cells is throwing the whole fuel cell out of balance over time to the point that even equalizing charge does not bring it back and then you just threw a $15,000 fuel cell out the window all because you to cheap to buy a $500 transformer

 

[Tony Stewart]

It is possible to modify a surplus 500W PC PSU for what you need. THese convert 90~240Vac to 12, 5, 3 -12. Cost ~$50 new , surplus free Read DIY sites.

80Vdc to 12V are rare but exist but expensive due to low volume. otherwise goto www.ti.com if you have experience, then DIY design in minutes.

expect $1/W cost
except PC PSU expect $0.15/W

 

[alec_t]

If you're not drawing too much current at 12V you could get away with using an old 110VAC input computer ATX power supply. Bypassing the input bridge rectifier may be the only mod needed.

 

[Tony Stewart]

I agree but some really old 250W PSU's required 5V 10% preload to regulate secondary Vout, like +12V when enable pin is grounded.