Hex Schmitt
2009
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 N T E 40106B INTEGRATED CIRCUIT HEX SCHMITT TRIGGER $4.99 Time Remaining: 12d 14h 20m Buy It Now for only: $4.99 |
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 Hex Inverter Schmitt Trigger DM74LS14N Lot of 23 $34.99 Time Remaining: 5d 2h 35m Buy It Now for only: $34.99 |
Hex Schmitt
voltage spike removal?
I want to add a switch to disable a signal to my sensitive device. However, the switching will have a volt spike.So i added a hex schmitt trigger invertor n go thru it twice. However, it seems unsteady sometimes, as the logic is sometimes wrong (IC is working fine). must i add capacitors or any other components? Pls help me, anyone?? or any better solutions? Will a regulator stop the spike?
Add:
Thanks. Is the Figure 2 the solution? Figure 1 is my initial set up. Just wondering why set up in Fig 1 doesnt work. I put my multimeter at point marked in blue, and toggled the switch, and the voltage at blue point doesnt change according to the switch. But it does change correctly at the red point.
Sounds like you need a switch debounce circuit.
Sometimes a switch does not make contact cleanly but jitters for a few microseconds as it is making or breaking. This is called switch bounce and it can be seen as multiple pulses by a logic circuit.
A simple debounce circuit would be to put a resistor between the output of the first inverter and the input of the second, and a capacitor to ground on the input of the second. It forms an RC filter which should filter out the bouncing pulses. Try a 2.2K resistor and a 1,000pF capacitor. If you still have problems, increase the capacitor.
Hex Schmitt Noise Box
