I have looked for a 36-volt nominal input to 14.2 volts regulated and
steady
output device for years, which is expected to survive more than one use and
be in the affordable range (under $150 retail). Never found one. I figure
there are plenty of automotive 12-volt devices I would like to run from the
whole pack - like winches, lighting, horns, etc.
My son the electronics tech says this is an easy unit to design and build.
However, he figures if he goes to the trouble of designing and testing one,
we should be looking to make a few to justify the effort. His question is,
what current rating is required(on the output side)? I have struggled with
that one. Price goes up with power handling. It's stepwise based on
components, so not quite linear (power/cost). The winch I am using seems
to
pull about 15 amps. I would likely rewire my original lifts to the 14
volts
from the sagging 18 to extend their life. Lighting will likely be a pretty
small load (thanks to LEDs).
So, is anybody else interested in a 36 nom to 14.2 regulated volts DC-DC
converter (fully isolated - 2 leads in, 2 leads out), and if so, what
current (output) would you consider desirable? If there is any response, I
will chat over the information provided with him over the holidays and see
what we can come up with. (I already know he'll say we don't need any new
projects - but my response is that we have been talking about this for so
long it's an old project <smile>.)
Darryl McMahon
On 22/12/2012 4:15 PM, The CZ Unit wrote:
On 12/22/2012 11:30 AM, Chris Tromley wrote:
For the lift, how big a deal is it to just run it on 36V? If it only
runs for a few seconds at a time and has plenty of cool-off time, why
would it hurt? If it is a problem, I wonder if you could use a cheapo
off-the-shelf scooter controller?
Honestly? I don't know. It probably would be ok, the problem is the lift
current breaker would probably fuse instantly if it tried to open due to
overload, that would be a problem.
Hm. Actually I have a bunch of apart-lift motors, I'll give it an honest
shot. The question is how do we current-limit it so the overload can
work? Maybe bypass it completely and use a 5 amp circuit breaker instead
of a fuse? What would be a good auto-reset 5-10 amp circuit breaker?
How common are 36V-to-12V DC/DC converters that would be suitable for
the lights? Are there any 48V input models that would still work with a
sagging 36V pack?
I used to use a Vicor DC-DC that would put out 12 volts for the um
E-meter and lights. But one morning I came out and found it had
literally blown up, which was odd. Might have been over-voltaged, but it
should have been able to handle up to 50 volts input.
Where I really need to limit current is on the sweeper. The motor on
that is just too darn fast, it beats up the brushes and the grass. Maybe
I could get a much smaller pulley or something.
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