But i have class this afternoon so ill go check out the Electronics closet to see if they have any ULN2004A or any ULN2804A's. ill keep you posted when i check it out

 

ok ill replace them but it still doesnt help with my Transistors....

Of course it will help your transistors.
The transistors turn off when the base voltage of the MPSA14 goes less than about 1V. A good CD4017 output goes to 0V.

 

The problem is that in order to get good saturation on the 2N2907, you need 1/10 collector current in the base. 300mA/10=30mA.

Try this:
Replace one of the MPSA14's with a 2N2222.
Change the 10k resistor from the 4017 output to 3k.
Change the resistor from the emitter of the 2N2222 to the base of the 2N2907 to a 390 Ohm resistor. You can use two 200 Ohm resistors in series.

 

Ok that sounds great ill try that... I was thinking about what you said in your previous post about the 4017 messing things up but when the 4017 is not plugged into the Transistor Circuit the lights Are still on.... so it has to be the MPSA14 or the 2097....

 

I have MPS2222A Is that the same as 2N2222?

 

Here, I re-drew the modification for you - just one channel though, to keep it simple.

Just replace one driver, and see how that works.

 

Ok that sounds great ill try that... I was thinking about what you said in your previous post about the 4017 messing things up but when the 4017 is not plugged into the Transistor Circuit the lights Are still on.... so it has to be the MPSA14 or the 2097....

I missed that. Of course there is something wrong with the transistors when they are turned on when they should be turned off.

 

It could be both.... Ill Buy new ones and replace them with brand new ones just to be sure

 

The 1k resistor to ground at the output of the CD4017 is not needed since its output goes to 0V when low.

 

Can i Use MPS2222A instead of 2N2222?

 

AudioGuru,
I know the 4017 output is supposed to go to 0v; the 1k pull-down is precautionary.

Stills00,
Yes, you can use the MPS2222A as a direct substitute for the PN/2N2222.

 

Ok so i did it and the lights still glow a little bit but they actually flash!!! the glow but then get bright when triggered by the 4017

 

Ok so i noticed something... Im only getting 3v out from the transistors... but then i replaced the 2907 because that couldnt be right and then the lights glowed brightly and did nothing... Im confused im going to get some new 2907's and then let you know what is wrong

 

So i got my hands on some ULN2003AN's But they dont have 2004's i know that the Resistor in the 2003 in 2.7kohms and the 2004 is 10.2kohms can we use the 2003's?

 

Yep. Give 'em a shot.
The outputs from the 4017 won't go as high as before, but that's OK. You'll still need roughly 390-400 Ohms between the outputs of the ULN2003's to the bases of the 2N2907's.

You also have to ground the GND terminal of the ULN2003.

The COM terminal of the ULN2003 can be left floating (disconnected). If you short it to ground, it will act as an LED test; all the outputs of the ULN2003 will be pulled down to around 0.8v.

 

Ok sor some reason i am getting .65 volts to the base of the MPS2222A which is keeping it on....

 

Holly Crap it works i had the 2222 Backwards!!!! Dude you rock!!!!

 

Wow. Were the MPSA14's backwards too?

 

I dont think so ill try it now

 

The MPSA14 has the same pin layout as the 2222.