I am basically a musician & part-time hobbyist. I am utilizing a 555 timer and a 4017b counter to work a series of colored light and sounds. The timer and counter are running off a 6 volt lantern battery. As I increase the speed of the 555 upward of 100 per second the effect with the colors and sounds blending together is amazing. This is such a basic application I feel bad that I cannot work it out myself.

I have a 12 volt / 7A battery that will adequately run my lights and sounds.

I used the output from the 4017b to switch an array of tip31 transistors. However, I cannot get the the transistors to pass more than 2 or 3 volts with very little current.

Can anyone recommend a transistor that would pass 12v/5-7A with the limited output of the 4017b counter. Thanks, AAC family.

 

Can you post a schematic? Something basic with MS Paint or drawn out and scanned in will suffice.

 

The usual mistake that beginners make is to try to run the lights from the emitter of the TIP31's. Move the lights to the collector side of the transistors to get full voltage.

Another mistake is believing that one transistor has enough current gain to drive several amps of current with only a few milliamps of drive on its base. This job requires more than one transistor, or maybe a Darlington transistor, or maybe a logic level MOSFET.

More information will get you better answers. Try to give us a drawing.

 

will do...

 

I will put together a drawing shortly. thx