industrial electrical suppliers such a Newark, Allied Electronics, Mouser, DigiKey are all good sources for bulbs. You may even find what you need via Radio Shack.
One hint about pilot lamps: once you determine the type of bulb (voltage & current rating) if you can then find a bulb of slightly higher voltage rating & if it will physically fit in, that bulb will last almost indefinitely because it is dissipating slightly less power. It will however, have a slightly reduced brightness which is typically a non-issue.
Joe's LED suggestion is also a good one; if you're familiar with basic electronics & soldering it's not that hard to figure out. Start with the measured supply voltage, figure on 15 to 20mA LED current, calculate the dropping resistor vaule as:
supply volts, minus ~1.5V for the LED. The voltage remainder dropped arcoss the power resistor / divided by the LED current = the resistance value.
Example: 20V supply - 1.5V LED = 18.5 V remainder.
18.5V / 0.02A = 925 ohms (use a 1k-ohm resistor).
Power is calculated as I * E: 18.5V * 0.02A = 0.37 watts.
This calls for a 1/2 watt resistor @1k ohm resistance value.
One hint about pilot lamps: once you determine the type of bulb (voltage & current rating) if you can then find a bulb of slightly higher voltage rating & if it will physically fit in, that bulb will last almost indefinitely because it is dissipating slightly less power. It will however, have a slightly reduced brightness which is typically a non-issue.
Joe's LED suggestion is also a good one; if you're familiar with basic electronics & soldering it's not that hard to figure out. Start with the measured supply voltage, figure on 15 to 20mA LED current, calculate the dropping resistor vaule as:
supply volts, minus ~1.5V for the LED. The voltage remainder dropped arcoss the power resistor / divided by the LED current = the resistance value.
Example: 20V supply - 1.5V LED = 18.5 V remainder.
18.5V / 0.02A = 925 ohms (use a 1k-ohm resistor).
Power is calculated as I * E: 18.5V * 0.02A = 0.37 watts.
This calls for a 1/2 watt resistor @1k ohm resistance value.