Hi All,
I've been working on responding to a reader request in Nuts & Volts for a 2-digit, 7-Segment counter. Attached is my, to date, complete, working schematic. Thanks to help from many members on this forum, I have a working model. I can submit this as is, but the engineer in me wonders if I can make some things simpler, reduce the parts count, etc. - all in all, make it more efficient. It works, so I really shouldn't beat a dead horse, but I'd like to ask a few questions and see if anyone has any additional constructive criticism.
1. There is a second attachment labeled Figures 1-4. Figure one is a circuit for making a momentary switch a power toggle switch. My implementation is in figure two. I'm using a 3V signal from a remote circuit, so I've used a MOSFET in place of the momentary switch. I've tried using a simple PNP and NPN transistor in place of the MOSFET to no avail. I originally wanted to use a T flip flop which sounds like it would do the same thing with less parts, but I had no joy making a dual D flip flop work as a T. Could a T flip flop work in place of this circuit?
2. Figures 3 and 4 show a CD4093 used to convert a 3V signal into a 5V signal and add debounce. Works really well, it just seems to be parts intensive. Is there a better way to do this?
3. Lastly, I'm planning to attempt to power the whole circuit with 12V since everything is CMOS and rated up to 15VDC, sans the remote circuit. This would allow me to get rid of the 5V regulator. Will update schematic if this works.
Any other suggestions or advice is greatly appreciated. Hoping others will be able to use this circuit for future projects.
I've been working on responding to a reader request in Nuts & Volts for a 2-digit, 7-Segment counter. Attached is my, to date, complete, working schematic. Thanks to help from many members on this forum, I have a working model. I can submit this as is, but the engineer in me wonders if I can make some things simpler, reduce the parts count, etc. - all in all, make it more efficient. It works, so I really shouldn't beat a dead horse, but I'd like to ask a few questions and see if anyone has any additional constructive criticism.
1. There is a second attachment labeled Figures 1-4. Figure one is a circuit for making a momentary switch a power toggle switch. My implementation is in figure two. I'm using a 3V signal from a remote circuit, so I've used a MOSFET in place of the momentary switch. I've tried using a simple PNP and NPN transistor in place of the MOSFET to no avail. I originally wanted to use a T flip flop which sounds like it would do the same thing with less parts, but I had no joy making a dual D flip flop work as a T. Could a T flip flop work in place of this circuit?
2. Figures 3 and 4 show a CD4093 used to convert a 3V signal into a 5V signal and add debounce. Works really well, it just seems to be parts intensive. Is there a better way to do this?
3. Lastly, I'm planning to attempt to power the whole circuit with 12V since everything is CMOS and rated up to 15VDC, sans the remote circuit. This would allow me to get rid of the 5V regulator. Will update schematic if this works.
Any other suggestions or advice is greatly appreciated. Hoping others will be able to use this circuit for future projects.
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