Can you substitute transistors?
Can you substitute transistors?
Fortunately it is normally possible to use a replacement transistor type as there is often a considerable degree of overlap between the specifications of different types of transistor, and by looking at the basic specifications it is normally possible to choose the correct transistor replacements.
What are the alternatives to using transistors?
Relays: Normally closed relays are all you need to make any logic gate. Normally open relays are also useful. Mag-amps: Magnetic amplifiers could be used to make logic gates similarly to transistor-transistor logic.
What is the gain value of 2N3904 transistor?
2N3904 is a NPN transistor hence the collector and emitter will be left open (Reverse biased) when the base pin is held at ground and will be closed (Forward biased) when a signal is provided to base pin. 2N3904 has a gain value of 300; this value determines the amplification capacity of the transistor.
What is the maximum current a 2N3904 can handle?
The 2N3904 is rated for a maximum of 40V between Collector and Emitter, and 200mA Collector current. Your circuit is only powered with 9V, and the current passing through each transistor is limited to less than 20mA, so any replacement that can handle eg. 20V and 100mA will be fine.
What are the capacitance and frequency of the n3904?
2N3904 Datasheet, Equivalent, Cross Reference Search. Operating Junction Temperature (Tj): 135 °C Transition Frequency (ft): 300 MHz Collector Capacitance (Cc): 4 pF Forward Current Transfer Ratio (hFE), MIN: 40.
What is a good substitute for a 2N3904?
At 10mA Collector current the 2N3904’s current gain could be anywhere between 100 and 300. Any substitute that is within or close to that range should be fine (assuming the circuit was designed to accommodate such a wide variation). In your circuit higher gain is better, but 100 is plenty enough.
