555 timer

Electric Motors and Controllers
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Rcblack79   1 mW

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555 timer

Post by Rcblack79 » May 16 2019 3:39pm

Hello ES. I will try to keep this post short so here goes. Is it possible to use the pwm out of the 555 timer and go into a mosfet gate driver. Ive been searching for an anwser on the internet with no luck. Im try to build my first dc motor speed controller possibly for high current and less than 100vdc. I know the 555 can switch the mosfet gate but my Qg is 132 nc i would like to switch around 10khz to 30khz. Will the 555 timer handle that much gate charge with minimal losses, i do realize a microcontroller will give me the best efficiency nut i have to crawl before i can walk. Im sure more information is needed for someone to help me i will gladly share. Thanks for any help

billvon   1 GW

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Re: 555 timer

Post by billvon » May 16 2019 5:15pm

Rcblack79 wrote:
May 16 2019 3:39pm
Hello ES. I will try to keep this post short so here goes. Is it possible to use the pwm out of the 555 timer and go into a mosfet gate driver.
Short answer - no. It is unsuited for the generation of PWM waveforms and for driving FETs. There are plenty of other IC's that are far more suitable. Are you using a brushed or brushless motor?
--bill von

Rcblack79   1 mW

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Re: 555 timer

Post by Rcblack79 » May 16 2019 5:48pm

Brushed for now

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Chalo   100 GW

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Re: 555 timer

Post by Chalo » May 16 2019 5:48pm

That sounds like an optimum solution for getting an e-bike to work for one minute out of every five.
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amberwolf   100 GW

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Re: 555 timer

Post by amberwolf » May 17 2019 1:23am

They've been used for very basic brushed motor controllers; this search will show you many:

https://www.google.com/search?q=555+motor+controller

But there are much better solutions out there--dedicated ICs like the motorola MC3303x chip Jeremy Harris based a whole controller thread around (at least one version of the chip can be a brushed or brushless controller core).

I'm sure there are others:
https://www.google.com/search?q=brushed ... troller+IC

KD5ZXG   10 W

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Re: 555 timer

Post by KD5ZXG » May 17 2019 10:52pm

http://www.ti.com/lit/ds/symlink/lmc555.pdf

Specs improved over the original version. 3MHz, 50mA.
I'm not reading in depth so maybe missing something...

Rcblack79   1 mW

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Re: 555 timer

Post by Rcblack79 » May 20 2019 10:20am

Thanks everyone for replies. I found a cool online calculator based on the 555 timer and how to set the pwm frequency i do have SE555 which can operate on higher temps vs its brothers and sisters in the same family. It may not be accurate, but it will give me a ball park number of the frequency im trying to generate based on resistors and cap values. Once again thanks every1.

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