Single output equivalent of ULN2003A Darlington Transistor Array? - Electronic Circuits Projects Diagrams Free

llrjt100 · 9th May 2006, 06:48 PM

Hi,

I'm controlling the brightness of a group of LEDs with a ULN2003A by PWM'ing the common GND. I need seperate control over the volume of a piezo buzzer using a similar device but only need one output, rather than the seven provided by the ULN2003A - I would be very grateful for suggestions as to a suitable device.

Thanks,
Richard

eblc1388 · 9th May 2006, 06:56 PM

Quote:

Originally Posted by llrjt100

I need seperate control over the volume of a piezo buzzer using a similar device but only need one output, rather than the seven provided by the ULN2003A - I would be very grateful for suggestions as to a suitable device.

Use one NPN transistor with a base resistor.

If you prefer, you can also look inside the ULN2003a datasheet, reproduced here for your convenience.

llrjt100 · 9th May 2006, 07:06 PM

I hadn't thought to look inside the data sheet like that - cunning stuff!

Thanks for your help!
Richard

philba · 9th May 2006, 08:18 PM

or, you could replace the ULN2003A with a ULN 2803A which has one more driver in it. everything else is the same.

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9th May 2006, 06:48 PM	(permalink)
llrjt100	Single output equivalent of ULN2003A Darlington Transistor Array? Hi, I'm controlling the brightness of a group of LEDs with a ULN2003A by PWM'ing the common GND. I need seperate control over the volume of a piezo buzzer using a similar device but only need one output, rather than the seven provided by the ULN2003A - I would be very grateful for suggestions as to a suitable device. Thanks, Richard

9th May 2006, 07:06 PM	(permalink)
llrjt100	I hadn't thought to look inside the data sheet like that - cunning stuff! Thanks for your help! Richard

9th May 2006, 08:18 PM	(permalink)
philba	or, you could replace the ULN2003A with a ULN 2803A which has one more driver in it. everything else is the same.