Hi,
what amount of current should a NPN transistor (low power) have going into its base when the emitter is grounded and the collector is used to switch a relay or somthing.
Ive always used a 1k base resistor driven from a 5V PIC micro output, which is
I = V/R
I = (5Vpic - 0.6vbe)/1000R
= 4.4mA
but was wondering if this is too much current?
The transistors are usually BC337 (500mA collector) or BC547 (100mA collector) depending upon what im switching.
what amount of current should a NPN transistor (low power) have going into its base when the emitter is grounded and the collector is used to switch a relay or somthing.
Ive always used a 1k base resistor driven from a 5V PIC micro output, which is
I = V/R
I = (5Vpic - 0.6vbe)/1000R
= 4.4mA
but was wondering if this is too much current?
The transistors are usually BC337 (500mA collector) or BC547 (100mA collector) depending upon what im switching.
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