Silent Radio with 4017

I added a 4017 to control the Silent Radio LED sign's row drivers and now it is much brighter and it can run on 9 volts.

Category:

Science & Technology

Tags:

• Silent
• Radio
• LED
• sign

[nrdesign1991]

Pro tip: Use ULN2803 for the LED cathodes and UDN2981 for the Anodes. The UDN's can switch up to 50 volts I think. They contain 8 drivers in one chip and can be easily put right after the shift registers. The ULN chips sink up to 500 mA. They're basically like 8 transistors in one chip thaat can be hooked up to the microcontroller's ports or shift registers. Good luck!

[bobdavis321]

@nrdesign1991 Thanks, I needed to source 500 ma hence the 4017 and 7 x TIP120. I am not familiar with the UDN2981

[nrdesign1991]

I'm happy to help. I used UDN2981's to switch 24 Volts DC with an ATMega32 microcontroller that can handle only 5 Volts DC. Works perfectly!