a bad power transistor, can have leakage and or weak hFe.
some testing does not find that unless done correctly
the 2SD1450 (yellow wire on ECU) low side.
this part is a superbeta part, (darlington they are) with a huge hFE gain. 4000. in fact it is 2 transistors in one package cascaded for gain huge.
ib at 2mA (.002) gets you at Ic. 8 amps. (ic = 4000x.002)
so use huge large Ib resistor. 10000 ohms or pot that big.
Type Designation: 2SD1415
Material of Transistor: Silicon.
Polarity: NPN (not pointing in, as we say for 55years me)
Maximum Collector Power Dissipation (Pc): 30 Watts
Maximum Collector-Base Voltage |Vcb|: 100 V
Maximum Collector-Emitter Voltage |Vce|: 100 V
Maximum Emitter-Base Voltage |Veb|: 5 V
Maximum Collector Current |Ic max|: 7 A ( yes amps and is how it runs 1ohm injectors)
Max. Operating Junction Temperature (Tj): 150 °C
Forward Current Transfer Ratio (hFE), MIN: 4000 (aka gain) or beta. Ic/iB gain, the transfer function.
some testing does not find that unless done correctly
the 2SD1450 (yellow wire on ECU) low side.
this part is a superbeta part, (darlington they are) with a huge hFE gain. 4000. in fact it is 2 transistors in one package cascaded for gain huge.
ib at 2mA (.002) gets you at Ic. 8 amps. (ic = 4000x.002)
so use huge large Ib resistor. 10000 ohms or pot that big.
Type Designation: 2SD1415
Material of Transistor: Silicon.
Polarity: NPN (not pointing in, as we say for 55years me)
Maximum Collector Power Dissipation (Pc): 30 Watts
Maximum Collector-Base Voltage |Vcb|: 100 V
Maximum Collector-Emitter Voltage |Vce|: 100 V
Maximum Emitter-Base Voltage |Veb|: 5 V
Maximum Collector Current |Ic max|: 7 A ( yes amps and is how it runs 1ohm injectors)
Max. Operating Junction Temperature (Tj): 150 °C
Forward Current Transfer Ratio (hFE), MIN: 4000 (aka gain) or beta. Ic/iB gain, the transfer function.
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