What is the benefit in getting shot of the relay and using a MOSFET if this is older technology.

Are they more reliable.

 

Because you would still have the transistor... and the relay.

The transistor can do it without the relay. I changed the kind of transistor to something better suited for the application. Q1 was in the same location for all the drawings.

 

Hi Bill,

I know you must be a v. busy man.

Have you had any time to look at the prototype yet.

Just asking, I am in no great rush.

Thanks

 

Sorry I didn't get back with you sooner. I've started the process, when I've got it somewhere I'll PM you (but you are welcome to look while I do it). AAC allows me to update the post indefinately, so I'll be modifying the attachment here as I work on it.

 

Thanks Bll, I will have a look at it tonight, the computer at work blocks Zip files!!!!

 

Bill,

It seems you are using a computer program.

Is this for illistration purposes only?

I tried the program "Tina" but could not figure it out.

 

Use a photo displayer, I'm drawing with M/S Paint. You can find the templates I use in my introduction in my blogs as PaintCAD.

Windows Picture and Fax Viewer is an excellent way to look at it, as it will print very legibally with no effort. Are you using XP?

 

Yeah Windows XP

 

It's not finished, but look at the files attached in post #44, and you can see where it is going.

 

Bill,

If you would be as kind to list the parts I would need for this build, when you get the time, I will buy the parts needed and use that diagram as a "where the bits go guide"

Thanks

 

But here's where I'm at now.

With the exception of the float switch and power supply (not sure about the Sonalert) all these parts are available from Radio Shack. Don't limit yourself however, RS tends to be expensive. If a part is mechanically different, such as the capacitors or Q2, don't sweat it, it will work.

 

Many thanks for this Bill.

I will get the parts oreder shortly along with a protoboard, and see how it works out.

Thanks again.

 

OK, here is the final product. You can use a short version of the protoboard to build it, and save space. The protoboard comes with sticky tape on the bottom to mount it.

Use superglue to tack the wires coming off the board down, being careful not to get any in the holes.

The LEDs can be moved after you've tested it and put it into a box (I assume you are going to do this).

If you have any problems drop a line.

 

Bill,

Quick question, C1, C2 & C3 0.1uf Capacitor the 1's I can find are 250v are these suitable??

I am just searching for the parts and I am getting them slowly.

The 556 IC the 1 I have found is a 556 dual timer and seems to have 14 pins is this correct it does look like the 1 in the diagram above.

I am just not sure on the voltage of all the parts or if it matters alot of them seem to be 50v!!

I also can find a 100K variable resistor.

Thanks for all your input on this.

 

OK, I said physical size isn't important, and it isn't, as long as it fits in the picture. The voltage rating is so high it just isn't important (12VDC compaired to 250VAC), but it has to mechanically fit in the space.

Yeah, I noticed you thought I had two chips, but what I had is 2 chips in one. This is pretty common in electronics nowdays.

Remember, all these parts are available at Radio Shack. Do you have one close to you?

 

I have an RS components that I use through my work.

It sells these parts.

I usually use www.rapidonline.com as they are cheaper, but the RS I refer to is maybe different to the RS you refer to, http://uk.rs-online.com/web/

I will use either, as long as they have the parts.

 

The pot is sold by RS for around $1.99, but BG Micro sells the same parts for $0.15. If you can find them from another source I say go for it. If you download my PaintCAD package you can find part numbers and relative physical dimensions in the bread board folder for the caps.

 

I will d/l the packages tonight and hopefully get the correct parts ordered.

 

I think I have found the correct variable resistor 0.2w @ 100v (horiz trimmer cremet 100k)

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=6524912

 

Hi Bill,

I have managed to aquire the exact same prototype board you have used, so laying out should be easier.

Parts will hopefully be here tommorrow.

Resistor R8 is that installed vertically. as it seems to be installed inserted in the holes that are right next to each other.