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555 timer help

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Well-Known Member
I haven't looked at your overall project, but you can prevent a 555 from triggering on power-up simply by returning the timing capacitor to +V (Vcc) instead of to GND. In other words, connect it in parallel with the timing resistor.


New Member
I started a thread in the micro controllers forum...


I've decided to go with a micro controller for sure. Today I began reading the manual for swordfish... it's a hell of a lot to take in when you havn't been exposed to this kind of thing before. I did take one programming class in High School (like 6 years ago) and we did spend a lot of time on Visual Basic, but I'm not sure if it's at all related.

As far as code, I'll take all the help I can get! But keep in mind, I do want to learn it too.


New Member
Try this

I have attached a Pdf with a schematic that will do what you have asked,
instead of using a 555 i have designed the correct opperation using 1 x 74HC02 CMos gate. Remember when using gates to ground all inputs that are not in use, in this case pins 12 and 13 as you will be using 3 of the four gates in this package. you can adjust the timing in the same manner as the 555 by changing the values of the 10uf cap. I teach electronics so i will give you a head start. Go to Yenka.com download the yenka program 57 Meg and when it asks for the registration select home user you will get a free licence as the product is designed for schools and you are allowed to have it for free at home to study on. this is a real time electronics sim that will allow you to design schematics and test them live on your PC eliminating the need to build or bread board. If you need to use a 555 there are many 555 examples you can start with and add or subtract components to suit your design. You will have fun. Good luck and keep building.


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