Peakfoto Digital Photo Still n Video wrote:
This is kind of bad boy charger like what Lee Hart shows, lower currents?
People generally refer to a A "bad boy" charger as just a bridge
rectifier straight off the 120vac line, perhaps with a resistor of some
kind to limit the peak current. The "resistor" could be a real resistor,
light bulbs, or just the total resistance of all the wiring and
connectors in the system. Such chargers are mainly useful for pack
voltages in the 96vdc to 132vdc range. Above that, the charging current
is negligible. Below that, the power wasted by the resistance becomes
excessive. The output is not isolated, and the voltage and current are
not regulated.
A "Bonn charger" is the same thing, with an inductor in place of the
resistor. It's a bit more efficient, since the inductor doesn't waste
the excess voltage, but instead lowers the power factor to limit the
current. Bonn chargers can work to much lower pack voltages, if the
inductor is big enough. But they have no voltage control; they act more
like a constant current source. Like the bad boy, the output is not
isolated, and is not regulated.
A "third world" charger is just a traditional transformer and rectifier.
The transformer's windings are chosen to get the desired maximum
charging voltage and maximum charging current. The vast majority of
cheap old battery chargers are this type. If well made, they are
efficient, rugged, and isolated. Drawbacks are the size and weight, and
that the output voltage and current is only as well regulated as the AC
line voltage.
Which type do you have? Or is it something else?
I have an AC light dimer... I could use a full wave bridge with that?
Yes, you could. This would be a phase controlled charger, like the K&W
BC-20.
Most light dimmers are too small to control a big high-current charger.
However, you can use a light dimmer to control the primary of a
120v-to-12v 10amp transformer. If your main charger is a simple
unregulated type like those described above, its output voltage will
vary with the AC line voltage. So wire the 12vac output of this
transformer in series with the 120vac input to your main charger. The
light dimmer can then add 0-12vac to the AC line voltage. Or if you swap
the transformer's secondary leads, it can subtract 0-12vac from the AC
line. Thus it can adjust the input to your main charger by +/-10%.
do you have diagram to build a SCR rectifier charger.
I have lots of them, ranging from simple to complex. It all depends on
how ambitious you are. Simple stupid ones only have half a dozen parts.
Better ones with good voltage and current regulation, safety timers,
etc. have more than a hundred parts.
--
A designer knows he has achieved perfection not when there is
nothing left to add, but when there is nothing left to take away.
-- Antoine de Saint Exupery
--
Lee A. Hart, http://www.sunrise-ev.com/LeesEVs.htm
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