These synchronous, presettable counters feature an inter- nal carry look-ahead for application in high-speed counting designs. The DM74LSA and. µç×ÓÆ÷¼þ²É¹º½Ì¨£ IC×ÊÁÏ²éÑ¯ÍøÕ¾£º µç×Ó¹ ¤³Ì¼ÊõÂÛ£º / 4 位二进制同步计数器（异步. 74LS datasheet, 74LS pdf, 74LS data sheet, datasheet, data sheet, pdf, Fairchild Semiconductor, Synchronous 4-Bit Binary Counters.
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As further issues arise I see dayasheet stuck once more with a dysfunctional circuit. Whenever I press the clock button I get all of the leds on except maybe one or two, with some flashing during the button press. I have added a debounce circuit, but still to avail.
Without this buffering, your switch should not work on a button push, only on a release. Get into the habit now.
(PDF) 74161 Datasheet download
Finally, you should not count on TTL outputs driving high, as you have shown. TTL works much better pulling loads down.
So your outputs should be connected like. You may object that this will provide LEDs which are on when the output is low, and off datashete the outputs are high, which is confusing. In that case, invert the signals going to your LEDs.
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That’s probably causing as much trouble as no debounce was. I’d reduce that down to something in the nF to 1uF range. Oh, Ill change that and see what happens.
74LS161 Synchronous 4-Bit Counter
So your outputs should be connected like simulate this circuit — Schematic created using Kc You may object that this will provide LEDs which are on when the output is low, and off when the outputs are high, which is confusing. Since you already need one section of aand there are 6 gates per IC, you simply go simulate this circuit.
WhatRoughBeast 49k 2 28 Okay I wired 7,9, and 10 together and then connected them to a 1K resistor to 5V. Then I used a pullup resistor for the clear switch. I switched the LEDs around and connected their input to 5V and their ground to the output pins. I’m still getting the same effect.
Also, have you added a 0.
74LS Datasheet pdf – Synchronous 4-Bit Binary Counters – Fairchild Semiconductor
I added a 0. It’s always the simple things. For a circuit board with a ground plane, the usual guideline is at least one cap per 5 ICs. For breadboards, use a cap for each IC. You can often get away with less, but as you’ve just learned, insufficient decoupling can have weird symptoms. Sign up or log in Sign up using Google.