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555 Timer Trouble

555 Timer Trouble

555 Timer Trouble

(OP)
Hi,

I recently tried to interface a 555 timer to a 4-bit up/down binary counter. I used a java calculator with circuit to design a frequency output of 2Hz(60% duty cycle). I etched the board and soldered all components. The counter wasn't functioning. I hooked up my scope to pin 3 and ground. There was no wave. Is there any suggestings? Should I get a better schematic and attach a schmitt trigger to pin 3 for a clean square wave?
Thanks very much!

RE: 555 Timer Trouble

hi,

working with 555 is a fun , send yr schematic , i will fix it.

RE: 555 Timer Trouble

hi..

RE: 555 Timer Trouble

I assume you want an astable (free oscillating) 555 circuit.  If so, the best astable 555 design is found on the Texas Instruments' 555 data sheet (see www.ti.com and search for '555')...

After reviewing the TI design, you should understand that Rb should be less than Ra for the 555 to oscillate.  It also helps to choose a small capacitor (0.01-0.5 uF range).  Since all you want to do is drive a counter, the "ON" duty cycle should be between 10%-40%, with edge triggered counters pulse width is not important.

Hope this helps.

-- Warpdrive.

RE: 555 Timer Trouble

Have you tried to OHM out your board to see if possibly  you have a short on your etched board ?????

have you tried to bread board you circuit  first  and also have you shorted pin 2 to pin 6???????

RE: 555 Timer Trouble

I need to make a calcultaor quick!! help!!!
dorilla@hotmail.com

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