Posted by Carl R. Vogt on November 23, 2000 at 05:51:55:
In Reply to: Re: Battery-Globe strob 250 posted by David Dierlam on November 22, 2000 at 21:20:38:: Is this voltage DC?
Yes 450vdc
All electronic flashes use high voltage dc regardless of the
supply voltage ( the batteries)
1. Most Battery units,use an Oscilator to convert the 6 or 12volt
DC to AC(this is the wineing sound you sometimes hear when a flash
charges), then a transformer raises the voltage to High Voltage AC
it is then rectified back to High Voltage DC. (a transformer only
works with AC) The Graflex 250 RG unit uses 5vdc Nicads and has a
transformer and oscillator to produce the 450vdc.
2. Some Battery units (Graflex 250)is simpler by using a High
Voltage battery they did not need the Oscilator, transformer, or
rectifier, the unit is much cheaper, but the batteries cost
more.
3. An AC plug in the wall unit uses the 120VAC and a transformer to
raise the voltage to 450VAC it is then rectified to 450VDC.
4. All strobe tubes work the same way, a high voltage is used to
charge the Capacitors. Typically some where from 360VDC to 500VDC
depending on the specifications of the flash tube. The high voltage
is applied accross the flash tube, a trigger transformer, delivers
a VERY high voltage spike to the middle of the tube (you can see
the trigger wire in the middle of the tube). This creates a path
through the ZENON gas and allows the high voltage to pass through
the tube (just like a lighting bolt) This cause the very bright
flash of very short duration (about 1/10,000 of a second) for non
automatic flashes.The light output (Watt/Seconds)is dependent on
the Voltage,size of the capacitors(mfd),and Duration. Hope this
helps
Carl