EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: queennikki1972 on May 03, 2019, 10:39:36 pm
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This simple circuit calls for a 74HC14 (x6) chip. Google shows it to be a 14 pin chip but the diagram only shows 2 connections and they are not numbered. The symbol looks like a inverter with only 2 connecting points.
Looks simple enough, but can someone explain? Maybe VCC pin to Grnd pin
http://solarbotics.net/library/circuits/misc_sound_wilfbird.html (http://solarbotics.net/library/circuits/misc_sound_wilfbird.html)
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The 74HC14 is a hex inverter, meaning it contains six individual inverter circuits. Each inverter has an input (1A, 2A, 3A, 4A, 5A, 6A) and an output (1Y, 2Y, 3Y, 4Y, 5Y, 6Y), and the Vcc and ground on the chip are shared.
The circuit schematic also uses six inverters, so it uses all six of the parts in the 'HC14. Since it doesn't matter which is which, they are not labeled except as "U1". If it did matter, then the symbols could be labeled "U1A" through "U1F".
(https://www.eevblog.com/forum/beginners/wilfs-bird-sound-circuit/?action=dlattach;attach=724881;image)
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Who is this Wilf of whom you speak?
There was a similar circuit published in Electronics Australia magazine May 1981 that might interest you.
https://archive.org/stream/EA1981/EA%201981-05%20May#page/n69/mode/2up
I noticed also they were talking about electric cars back then too on page 12.
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Yeah I know, old circuits, but its how I learn. I printed page 71 of this article for the circuit because its a little different
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Yes, it's a good idea to start with old, proven designs.
Regarding the schematic linked to in the first post: not only are the power supply pins not shown, but there's no decoupling capacitor. Connect a 100nF capacitor between pins 7 and 14, as close to the IC as possible. You may be able to get away without it, especially with the 74C14, rather than the 74HC14 IC, but it's good practise.