neptune Posted February 4, 2010 Report Share Posted February 4, 2010 This is my first post here.Well i want to make this to store information .i provided a block diagram for this. I am currently testing it for one 40174 IC only.I am using 9V as power supply.The problem is output LED's start to flicker with 555 frequency.ON OFF sequence.problem is still there no matter where i connect input of 40174 to high or low. ???any suggestion would be appreciated. Quote Link to comment Share on other sites More sharing options...
audioguru Posted February 4, 2010 Report Share Posted February 4, 2010 Hello again,Your circuit is still missing the supply bypass capacitors and CLEAR-not pin connection that were discussed on the other website. The supply bypass capacitors are very important if you use a weak little 9V battery and a high power 555 since the 555 causes a 400mA current spike each time its output changes that drops the supply voltage to the CD40174 IC. Maybe you should use a Cmos 555.The clock for the CD40174 is not supposed to be an oscillator. Each flip-flop stores the logic-level that is at its D-input when the clock goes high. If you stop your 555 clock then the CD40174 will store the bits. Quote Link to comment Share on other sites More sharing options...
neptune Posted February 4, 2010 Author Report Share Posted February 4, 2010 maybe i have to redesign my circuit. Quote Link to comment Share on other sites More sharing options...
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