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Converting Ac to Dc current.
benchmark:
--- Quote from: picclock on January 19, 2011, 05:18:35 PM ---Hi Benchmark
If you connect the windings in series, getting the phase right to give you 150 volts you can connect that to a redundant mobile phone charger (hide it in the base). They will normally run from 100 - 240v AC and they are not fussy about frequency. The output of these is normally 4-5 volts, just right for running some LED's (via a resister :zap:) and small bulb's from. If you remove the charger case the electronics are quite small. the largest thing about them is the mains connector, just remove that and solder your generator wires to the connections.
Good luck and show us the pictures.
picclock
--- End quote ---
Thanks for the response but the problem with this will be that the gen wont make any current when the engine is running slow since the phone charger need minimum of 100 volts to work.
What if i just connected the resistor in series in a Half-wave rectification with a single diode in a one-phase supply. Like this
how many volts will i get DC? and con someone please explain to me what 'R' stands for in the diagram above? finally what diode can i use for this, the same bridge rectifier diode linked by BillTodd?
BillTodd:
--- Quote from: picclock on January 19, 2011, 05:18:35 PM ---Hi Benchmark
If you connect the windings in series, getting the phase right to give you 150 volts you can connect that to a redundant mobile phone charger (hide it in the base). They will normally run from 100 - 240v AC and they are not fussy about frequency. The output of these is normally 4-5 volts, just right for running some LED's (via a resister :zap:) and small bulb's from. If you remove the charger case the electronics are quite small. the largest thing about them is the mains connector, just remove that and solder your generator wires to the connections.
Good luck and show us the pictures.
picclock
--- End quote ---
I like that idea :) but the stepper phases are likely to partly cancel if series connected, probably better to rectify first (switch mode PSUs will work happily with a DC input)
Bill
picclock:
@ Bill
My Bad :hammer: - the phases for a std stepper are 90 degrees out of phase. Not sure it would make much difference as this would still put the rms value @ 110 volts, and most of these chargers will work down to 90v or less depending on load. I would think that is worth a try.
Technically better option as you say is to bridge rectify both windings, with capacitor smoothing, and connect the outputs in series as this will result in the smallest motor load.
@ Benchmark
Half wave rectification results in a dc current flowing through the windings which is likely to demagnetise the magnet in the motor. Much kinder to the motor to use fullwave rectification, as it reduces the current peaks into the load and works the magnetic motor components about the centre point. If it helps think of it as an unbalanced flywheel .. . it will work but the bearings will be shot in no time.
The R in the circuit is the load. Without an input capacitor the average voltage is 66 % of the peak - so 75 volts is 106v peak, or 70volts average. As its half wave rectified you would think 35 volts but things are much more complicated than that. As an example, a 35 ohm resistor will draw 1 amp at 35 volts, dissipation 35 Watts. However doubling the voltage will give 2 amps but 140 Watts.
IMHO try the two windings in series and a phone charger. Its quick to do, and will allow a large current draw at a lower voltage which is what you need for LED's and bling lamps. As a bonus the output is isolated so no nasty shocks.
The frequency of operation will not matter much for a device like this.
Good Luck
picclock
BillTodd:
--- Quote ---Not sure it would make much difference as this would still put the rms value @ 110 volts, and most of these chargers will work down to 90v or less depending on load. I would think that is worth a try.
--- End quote ---
I agree , well worth trying especially for a simple application like this :)
Bill
benchmark:
Well Guys, the rectifying diodes came yesterday and i finally finished the generator and it is performing well above my expectations.
I will let the video speak for itself
Thanks for all the input.
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