Click here for full specification sheet.
Click here to view DH165A0 Instructions
I am installing a DH165A0 in an Athearn SD70. The Head light outputs are a nominal 30 ma (with the link cut). The bulbs I am using are a bit lower in their current demands and [my lamps keep burning out].
Is there any way to lower the current output from 30ma, or do I need to add a resistor in line with the bulb to drop the voltage output? Of course, if it is supposed to be a regulated current output this might be a problem.
The Theoretical Answer:
The DH165A0 has a constant current source for F0F and F0R, so a series resistor will simply increase the terminal voltage at the selected fixed current.
To drop the lamp current, add a resistor in parallel with the lamp to bypass some of the current selected, calculating value for the resistor: (R = Lamp Voltage / amount of current to divert). If the resistor is too small a value it will bypass more of the current and the lamp will be dimmer. You can try a number of values to get the best "fit"
A More Practical Answer:
If the filament lamp is burning out, try putting a 47 ohm resistor in parallel. If it's still too bright, gradually *decrease* the resistor value.