Short: replacing NPN 2n3904 with BC337 to drive an OMRAM G8P relay
I have a broken vacuum, the power PCB burnt up a diode(Unknown value) and NPN(2n3904), they controlled the main vac motors relay. I replaced the 2N with the BC device I found in my spare parts. Now the vac "works" but not safely, it powers on but not off correctly.
The 2N's base is driven by a custom Xilinx chip thru a 470 Ohm resistor. Without modifying the Xilinx firmware what do I need to change?
I droped out of my Electronics class because I can't read Resistor colorcodes being color-blind. To bad we didn't have all these SMT goodies back then, with thier nice clear but small labeling..
I "think" I need to loose .3v for the for the new NPN's base, is that correct?
That would mean adding resistance?
Question 2: Any guesses at the diode value and orientation?
It was connected between the Relays coil pins, pins 2 and 6. It was just a spot of carbon before I removed it, so was unreadable.
The relay switches at 75% and 10% of 12V.
The Old NPN
..
h
I have a broken vacuum, the power PCB burnt up a diode(Unknown value) and NPN(2n3904), they controlled the main vac motors relay. I replaced the 2N with the BC device I found in my spare parts. Now the vac "works" but not safely, it powers on but not off correctly.
The 2N's base is driven by a custom Xilinx chip thru a 470 Ohm resistor. Without modifying the Xilinx firmware what do I need to change?
I droped out of my Electronics class because I can't read Resistor colorcodes being color-blind. To bad we didn't have all these SMT goodies back then, with thier nice clear but small labeling..
I "think" I need to loose .3v for the for the new NPN's base, is that correct?
That would mean adding resistance?
Question 2: Any guesses at the diode value and orientation?
It was connected between the Relays coil pins, pins 2 and 6. It was just a spot of carbon before I removed it, so was unreadable.
The relay switches at 75% and 10% of 12V.
The Old NPN
..
h
FE* DC Current Gain
IC = 0.1 mA VCE = 1 V Min 60
IC = 1 mA VCE = 1 V Min 80
IC = 10 mA VCE = 1 V Min 100
IC = 50 mA VCE = 1 V Min 60
IC = 100 mA VCE = 1 V Min 30
IC = 1 mA VCE = 1 V Min 80
IC = 10 mA VCE = 1 V Min 100
IC = 50 mA VCE = 1 V Min 60
IC = 100 mA VCE = 1 V Min 30
All Max 300
..
..
The New
..
h
..
h
FE* DC Current Gain
Relay data sheet:
http://downloads.components.omron.e...r Relays/Up to 30A/G8P/K108/K108-E2-03A-X.pdf
NPN datasheets I got off the datasheetcatalog.com web site (I assumed they were from STmicro, the bulk of the chips are..)
IC = 100 mA VCE = 1 V
Min 160 max 250
..
Min 160 max 250
..
Relay data sheet:
http://downloads.components.omron.e...r Relays/Up to 30A/G8P/K108/K108-E2-03A-X.pdf
NPN datasheets I got off the datasheetcatalog.com web site (I assumed they were from STmicro, the bulk of the chips are..)