Railfan Technology > Locomotive Gyra light SP power supply info needed.

Looking for information to order a power supply for the dual head light. Lamps are 32 volt DC x 2.  = 64 volts/ the motor is 24V DC on the head light. My question is what type of Amps are needed to drive each,. my assumption is that I will be needing two power supply's, one 24 v. DC for the gyra motot and the 64 v DC PS for the tw lamps, amazon has them for 60 V DC, at not a bad price. I think it is 5 amp max. for about $85.00

I also have one Red ball emergancy light as well which has one lamp 32 v DC and the 24 v motor. 



Edited 2 time(s). Last edit at 11/27/22 11:23 by czuleget.

You need to determine the wattage of the bulbs.  Look for markings on them, but the size can tell the story.  The 5.75 inch, PAR46 bulb is likely 150 Watts at 32 V.  The 7 inch, PAR56 bulb is likely 200 Watts at 30 V.  To get the current (Amps), we divide Watts by Volts.

PAR46:  150 / 32 = 4.7 Amps

PAR56:  200 / 30 = 6.7 Amps  Because the lamp draws more current at 32 V, let's call it 7.1 Amps

Since you intend to run the lamps in series, the current ratings above apply to the 64 V supply.  Get a supply rated for more a few more amps than calculated.

Those lights will be crazy bright at full voltage.  If you want to dramatically extend lamp life, and save your eyes, run them at a lower voltage.  48 Volts is fairly common in off the shelf supplies.  Another thing to consider is that lamps don't care whether the power is AC or DC.  You could use an AC transformer instead of a DC supply.

On the SP we had a Mars light mounted on a simple 3/4” plywood frame, powered by an AC motor. You could just plug it into a standard 120 volt AC outlet and it was running and illuminated. Very useful in a courtroom to show how the beam of light warned of an approaching train.