| Electronics > Projects, Designs, and Technical Stuff |
| Need help designing a load selector! |
| << < (4/7) > >> |
| MarkF:
One of your counter chips will give you 4 bit binary count. You can use the NAND gate(s) to create the 'Data' input to the shift register. Refer to the timing diagram I added a few posts back. |
| WyverntekGameRepairs:
All right. So what is the schematic looking like now? |
| MarkF:
Maybe some partial testing is needed here. Take the last circuit posted and remove the SN74196 decade counter. Testing the CD4094 and LEDs: Then manually clock in all 1's followed by all 0's and verify the shift register and LEDs are working. - Tie 'Data' pin (2) high. - Press the switch five times. (all LEDs should turn 'On' one at a time) - Tie 'Data' pin (2) low. - Press the switch five more times. (all LEDs should turn 'Off' one at a time) Then, you can figure out the logic to generate the 'Data' input signal. |
| MarkF:
I found an error: The Output Enable (pin 15) and Stobe (pin 1) both need to be 'High'. I have the wrong chip on the drawing. |
| MarkF:
It appears that I miss-read you original post several times.... You never ask to have ALL LEDs On at one time. Just sequence through and one all Off state. I think I fixed the startup initialization. The RC time constant may be too short for the LOAD pin. |
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