transistor req help

[markosillypig]

h i am making this circuit i have altered it from the original one could any one tell me that i could use as Q1 to Q10 for 500 MA or above say 750MA and what the value of resistors i need for the Q1 to Q10
thanks

[mik3]

What is the output voltage of U2 and how much current each output can source?

[markosillypig]

4.95 volts x 500 MW if this helps

[mik3]

The maximum output current of U2 when it is power with 5V is 0.36 mA. Thus you will need a 12K resistor for each transistor. Also, you have to use darlington transistors which have a gain greater than 1500 at saturation.

[markosillypig]

will a TIP23 do the job or can you recomend something else i have in stock some IRF530's

[mik3]

The IRF530 is not a logic level MOS. It needs 10V to fully turn on however you may use it because the current through it will be only 500mA. Try one and if it gets very hot then you have to use another one or power U2 with 10V.

I can't find TIP23.

[markosillypig]

sorry tip32

[mik3]

Originally Posted by markosillypig

sorry tip32

Its gain its too low, you can't use it.

[hgmjr]

You are going to need to use a different regulator than the 78L08 since it is only rated for 100 milliamps maximum.

hgmjr

[markosillypig]

i have the 78l08 so i will replace it