Building an adjustable clock source and using it to count to 255
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- Опубліковано 19 сер 2024
- A digital circuit project I have in mind may need a clock I can start, stop, and step so I built Ben Eater's adjustable clock module (with some modifications) and hooked it up to an 8-bit counter with pretty blue LEDs.
-- Links
Ben Eater's clock module page: eater.net/8bit...
Ben Eater's clock module videos: • Astable 555 timer - 8-... , • Monostable 555 timer -... , • Bistable 555 - 8-bit c... , • Clock logic - 8-bit co...
Texas Instruments xx555 Precision Timers Datasheet: www.ti.com/lit...
Texas Instruments SN74LS51 And-Or-Invert Datasheet: www.ti.com/lit...
Texas Instruments SN74LS04 Hex Inverters Datasheet: www.ti.com/lit...
Texas Instruments SN74LS190 Up/Down Counters Datasheet: www.ti.com/lit...
555 Timer Calculator: www.build-elec...
-- Stuff
TTL ICs: amzn.to/40WH75c
Chip Assortment Kit (with NE555): amzn.to/3x9cb6I
Tiny DPDT slide switches: amzn.to/3wVl97H
Assortment of push buttons: amzn.to/4a1A0Mv
Potentiometer variety pack: amzn.to/3PmPGBG
Very nice breadboards: amzn.to/3TkNPOY
BB830 Solderless Breadboards: amzn.to/3uAYxIE
Breadboard kit with components: amzn.to/3MYwfho
Multimeter: amzn.to/49PUg45
Antistatic mat: amzn.to/49RhcQi
My Wife's Books: amzn.to/47yt9Ji
(Maybe you and/or someone you know will like them!)
I've been thinking about why this is working for me so well (apart from the good sound, *wink*): I've dabbled in electronics. I have used breadboards, cables, LEDs, resistors, soldering irons.. but often lacked the patience for such a methodical approach. I also actually don't really want to spend a lot of time in electronics, but I find it relaxing, entertaining and generally enlightening to watch others problem solve. I think you've hit on a format that's akin to watching others play games. And the fact that it all fits in a square on a desk makes it that much more concentrated. Keep them coming, I'll be watching.
Glad you're enjoying them! (Plus, I had a good sound coach! 😉)
I found your ic videos like with the 7 segment and all the ic videos so interesting, keep it up!
Glad you liked them!
Those 4 gates (2x7408, 7404and 7432) can be replaced with an equivalent circuit made by the 4 gates in an 7400 IC. Try to read about logic minimization. Can save you a lot of ICs and traces on a PCB.
This is the way to go. Two and gates feeding an or gate is logically equivalent to 3 nand gates. Only one chip.
@@geeko321 yes, and the last NAND gate used as inverter. There you have an 7400 fully used.
Something so satisfying about that level of efficiency.
20:51 You observe that the chip is warm. The total chip current (typical) is 65mA. You don't mention the resistor values of your LEDs, but assuming all 8 LEDs are on, I suggest a resistor value of at least 320ohms so as not to stress the chip. That keeps things at about 5mA/LED which should be a safe value and sufficient to light them as well.
I happened to use 1K on each LED for this circuit, so it sounds like this should probably be fine. Maybe these particular chips (or these from this particular manufacturer) just run a bit warm or something?
@@bigzaphod Right, 1K should be fine. So yeah, maybe they are knockoffs. Could be depending upon where you purchased them from.
Good stuff. I'm wondering if you skipping some of this made it remove part of the debounce mechanism of this circuit.
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