lamp ballast power transistor
Tanuki,
Here's the best I can do:
1. What is the value of the snubber capacitor? .033 K 630
2. What is the resistance across the lamp heater pins? If we mean resistance across the pins of the lamp itself, when not connected to the circuit, it is between 20 and 30 ohms. Between the two red wires at the lamp socket, 10 ohms. Between the two blue wires at the lamp socket 150 K
3. Also, on your working unit that has the similar inverter and wattage lamp, what is the AC voltage across the lamp when operating? Take Care!
I do not have a working model of the same wattage here in the mountains (again). I plan to visit the boat later in the week again, and can bring a single tube working model up for these measurements.
4. One last item, if you have a amp meter, when the inverter is operating, what is the supply current to the inverter (black wire) and the supply voltage?
I do not have a working model of the same wattage here in the mountains (again). The supply voltage comes from the battery bank on the boat, and is ranges from 11 volts (batteries very low) to almost 14 volts (chargers powered by shore line, wind generator, or onboard gen set going full blast). As above, I will bring a working unit for this measurement later in the week.
5. "guessing that the inverter operates around 40KHz,"..Note that the patent specifies "between 15 and 25 kHz, preferably about 20kHz."
The snubber cap only exists on the 30 watt units (which use larger tubes), but again, neither of the 30 watt units failed, only the 8 and 16 watt units failed.
Should I go ahead and put in a new 2N3055 (or equiv.) on the single-tube failed unit that I have and see if it will work? Then I could do the other tests....
Kip