80v to 100v dc dc converter needed

drewjet

10 kW
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Jan 23, 2008
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Location
Orlando, FL USA
I am upping the voltage on my Suzuki to 85 volts and will need a new DC to DC Converter. My old Artysen only went to 75 volts so I need a new one, but am not having any luck. I need something that will go from say 60 volts to 100 volts input and 12v output. It needs to be isolated as I actually need 12 and 24 volts and I use 2 of them in series to get the 24V

Any ideas?
 
I am trying to understand the high voltage (say 100 V) to xx V DC to DC converter usage in the field. Interesting that you are going to 24 volts final, may I ask what the load is? If you had a 100V to 24V converter would it still need to be isolated? The reason I ask is the lower the conversion ratio, the easier it is on the electronics.
 
Laptop power supply.

Commonly 80-250VAC or VDC input (even though they often only list 100vac-240vac), 14-20vdc output a 3-4-5-6amps depending on the type. High conversion efficiency, and often able to be waterproofed with just a careful smear of silicone over the seams and screw holes. Isolated. Often available on ebay for under $15-20usd shipped.

Parallel outputs if you require additional current.


Here is a 5Amp 15vdc model for $11 shipped:

http://cgi.ebay.com/New-Power-Supply-Charger-Cord-Toshiba-Laptop-15V-5A-/280422201445?pt=Laptop_Adapters_Chargers&hash=item414a773865
 
I need 24 volts for my headlight, tail light, master relay, horn and also the controller. I need 12 volts for the turn signals. It was after I ordered new lipo at a higher voltage than I am currently at that I realized the need for a new DC DC converter. I know that I could tap off the first 3 series of 5 cell packs,(15S) and run my current converters from that, and I may till I get a good solution, but it will slightly imbalance the packs. It won't be a major problem as I balance charge with RC chargers every charge, but I would rather do it right.

Thanks LFP I will look into those, but I really need it to be a 12 volt outputs
 
They offer them in different voltages. Older lappys were 11-13vdc while they were running 3s lithium packs, then they moved to 4s, and now 5s is becoming common, so you see them in the 19-20-21v range often. Check around on fleabay.
 
As long as your current needs are low, those switching power supplies work great, and it's likely you have some sitting around the house already. I've tested the one I use all the way down to 60V dc input. Due to the low current output, you'll probably need one for 12V and one outputting 24V, though your lighting may need to be LEDs to have enough current.

John
 
drewjet said:
I need 24 volts for my headlight, tail light, master relay, horn and also the controller.

Thanks LFP I will look into those, but I really need it to be a 12 volt outputs


What a pain with all those different accessories at different voltages. I would change them for standard motorcycle gear. The 15V supply LFP linked will likely give 14-14.5V at the end of your wiring. That's what the charging voltage is on 12V car/mc systems anyway. If you go 12V and run car/mc stuff they will glow dimmer. Or if you;re concerend put a 0.7V silicone diode in series with the 15V output for 14.3V.

To get a small 12V supply, look in the halogen lighting department for switched supplies (the lightweight ones) in home stores. Note some pf these output 40-100kHz AC. I bought a couple of these for $10 each at Homedepot. First put a normal bridge rectifier on them, but that ran hot (due to high switching frequency). Then scavanged the HF schottky diodes from a couple of dead PC PSUs. This works fine, but as I said, on 12V sharp the "12V nominal" lighting glows a bit dim.

For more amps you can buy a Meanwell S350-13.5 for about $30-40 on ebay. These are not waterproof though.
 
drewjet said:
I need 12 volts for the turn signals.

isn't it easier to only replace your turn signals with led's with the right resisitor so the can run on 24V?
 
Ditto on the laptop power supplies. Some of them I've seen at 5A output or higher. I think the 19V brick I use for boosting pack voltage to my CFLs on CrazyBike2 is 3A, and it's not even an inch thick by maybe 4" long and a couple inches wide. Could be made significantly smaller without the plastic casing. (probably could run a higher load, too, since it'd cool quicker).
 
auraslip said:
Noob question, but do these need a pre-charge resistor? Or can I just use a normal spst 20 amp 125 VAC switch between the battery and the power supply?

Just a switch should be fine.
 
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