need some help

[kychin]

i got problem doing my project now. All the component type and code have given but just the transistor only don't have given. Can any pro help me check this circuit use what type transistor?


here is the circuit diagram using LiveWire

**broken link removed**

 

[MikeMl]

Since the transistors are driving LEDs that in turn are driven through the CMOS 4066s, the current through them is a few 10s of mA, so almost any NPN garden-variety switching transistor like a 2n3904 will work.

 

[kychin]

Since the transistors are driving LEDs that in turn are driven through the CMOS 4066s, the current through them is a few 10s of mA, so almost any NPN garden-variety switching transistor like a 2n3904 will work.

ok, i got use 2n3904. But don't know why i solder all the component in pcb, it don't work properly. what is the problem?

here is my pcb diagram
**broken link removed**

 

[mneary]

The pin arrangement for the transistor in the metal can on your diagram is not the same as the plastic 2N3904.

Read the data sheet of the 2N3904 and you might be able to bend the leads to go into the right holes. Or use the correct PCB pattern for the transistor and it will hook up correctly.