Need a little help and understanding of a 555 timer circuit.

[coryjones]

Here is what i am trying to do i want to turn a dc pump on and off faster then 1 second intervals. Basically this is being used to create waves in a reef tank. I have found people doing this with three wire tunze pumps but i have a 2 wire resun. I have built 2 types and they have both failed. I don't know if it is because the pump draws 1.5 amps and is 24 v dc.

Is there a good article or better yet a video on how the 555 timers work? I see people making leds flash with them so i should be able to get this pump to turn on and of right? The first one i built was this but could not get it to work i am not sure where my positive and negitive in and out go.**broken link removed**


I use to play more with electronics back in high school and would like to get back in to them and get my son in to them as well.

 

[tcmtech]

I doubt your pump motor will actauly be able to speed up and slow down in one second or less. Plus that much start and stop cycling will could kill the motor too!


For short waves a simple mechanical motorized bobber would probibly do much better.

 

[coryjones]

This is what i want to do but instead of a speaker run a pump.YouTube - 555 timer bomb timer sound maker


This is what the finished product looks like i can find videos of people having done it but no one saying how they did it.YouTube - Twin Resun Wave Box

 

[coryjones]

These guys are saying that they work fin long term it is not speeding up and down it is turning off and on.

 

[coryjones]

It would take a larg bobber to make 90 gallons swell but if you have any ideas i am open to them.

I doubt your pump motor will actauly be able to speed up and slow down in one second or less. Plus that much start and stop cycling will could kill the motor too!


For short waves a simple mechanical motorized bobber would probibly do much better.

 

[k7elp60]

With the diagram you posted Pin 1, is the output,Pin 2 is the - supply, and Pin 3 is the + supply. Most 555's have a maximum supply voltage of 18V. The 555 will not drive the motor directly, but it will drive a power mosfet to turn the motor on and off.

 

[coryjones]

Ok I looked up power mosfet and it looks to me to be kinda a relay that can come on and off quickly. Is this right? anyone willing to help me design a circuit to get this to work? I would really appreciate it and my Corals would too. I want to make this work there is a lot of people out there that would like to figure out how to build this.

 

[coryjones]

I am not sure what you mean there is no pin 3 there is 1 2 and 5 So what is the output + or -? I would assume it is positive with the cap going across it right? This pump will run at 12v and the power supply is adjustable so maybe i will rebuild it and try it at 12v for starters.

With the diagram you posted Pin is the output,Pin 2 is the - supply, and Pin 3 is the + supply. Most 555's have a maximum supply voltage of 18V. The 555 will not drive the motor directly, but it will drive a power mosfet to turn the motor on and off.

 

[colin55]

What MOSFET did you use?

 

[coryjones]

I have not used one it was just suggested.

 

[smanches]

It's not just suggested, but needed. The amount of current a motor draws is magnitudes greater than what the chip can supply. You need the mosfet to act as a high power switch that is controlled by the 555 IC.

 

[coryjones]

So what one would you suggest and how would i add it?

 

[k7elp60]

So what one would you suggest and how would i add it?

Please see my original post for some corrections.
I would recommend and IRFZ44 n channel mosfet, and suggested circuit is posted.

 

[colin55]

Now draw a 555 as a schematic - not as a "layout" above - so you can see how the chip is operating, and add the MOSFET and motor section (as shown above).
I can then comment on your circuit.

<mod edit: self promotion deleted. If you have content to share, please post directly to ETO. Do not link to your own personal website.>

 

[coryjones]

I did not draw that someone else did. I will do the reading up on what you suggested thanks for the help.

 

[coryjones]

This is thie post it is in on Reef central and the second one is one that i posted and a guy is trying to rebuild it for the purpose if you are interested.

Reef Central Online Community - DIY Wavebox Tutorial from start to finish!

Reef Central Online Community - Diy resun wave box

 

[blueroomelectronics]

I take it you don't have the controller used in the original thread?
**broken link removed**

 

[coryjones]

This is a diffrent type of pump i do have the contrller for this one but i don't think it will be of much use. It changes speeds every few seconds by changing the voltage.

 

[colin55]

You have to be more specific. We have absolutley no idea what you are talking about.

It's a bit like:
They have this thing. They clip it onto my wrists when I do soldering.

Who would know I am in prision and when I work in the laboratory, they hand-cuff me?

 

[coryjones]

Here is what i want it to do. I have a 24v dc pump i want it to turn of and on very quickly. From 1 second to steady on. It draws 1.5 amp max the circuit that i listed is for a dc pump but it is setup for a controller that comes with it. I dont know what is in the controller and dont care. I am just trying to build a curciut to turn this pump i have on and off quickly. I am not sure what else you want to know.