# need help

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#### Geno03245

##### New Member
I have a reversible 12V dc gear motor. I want to design a timer for the motor that works similarly to a reversing garage door opener circuit.

The timer sequence is as follows: A circuit is activated and the motor runs 25-35 seconds. After 25-35 seconds the motor stops, the circuit is closed AND reset for reverse. The next time the circuit is opened, the motor runs for 35 seconds in reverse. Afterward the circuit is reset for reverse again.

I have been catching up a bit on electronics the past weeks, but remain a total novice > however I understand household circuitry. My website is waterheatertimer.org. I have a simple 'off-the-shelf' solution for electric water heater timers, but don't have a solution for gas water heaters. My design idea is for a retrofit on a gas water heater that moves the control dial between 'vacation' and the thermostatic setting. The 12V dc motor would retrofit over the water heater control dial > I am trying to find a timer to apply specific control over the motor.

Any suggestions?

#### MikeMl

##### Well-Known Member
First, a permanent magnet DC motor has just two leads and which direction it runs is determined by the direction of the current through it. The reversing circuit uses two relays, or four FETs in an H-Bridge circuit.

It would seem to me that rather than using time to determine how far the motor runs in your application, you should be using limit switches. That way, the motor runs until it is stopped at a specific angle.

#### Geno03245

##### New Member
Limit switches are a solution except for size constraints. I was hoping for a clean motor + circuit board solution.

Is there a circuit that will reverse at the end of each cycle > and apply time control to a 12V dc motor?

#### nike6

##### Banned
on the website: I will also sell parts

should be a .COM, not a .ORG

.COM - commercial
.ORG - organisation
.INFO - gateway/personal homepage
.BIZ - business (not compulsory, less adoption than .COM, rather a proposal)
.GOV - government
.EDU - educational
.JP - permanent residual address required, you can not just have such a domain address.

.CO.UK - Britain only but not legally binding

#### MikeMl

##### Well-Known Member
Limit switches are a solution except for size constraints. I was hoping for a clean motor + circuit board solution.

Is there a circuit that will reverse at the end of each cycle > and apply time control to a 12V dc motor?

Divide and conquer. First, the ubiquitous 555 timer chip configured as a one-shot will generate a signal which is high for the motor run duration. The 555 could also toggle a flip-flop which dictates the direction the motor will run.

So, a 555, a CMOS D flip-flop like a 4013 wired as a toggle, 2 P Fets and 2 N Fets to drive the motor will do it.

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#### nike6

##### Banned
there are many control circuits in this book, and it can be beneficiary for anyone into electronics. it is still being printed and sold.

I am sure the OP could find impressions and/or circuits similar to the OP's requirement in this book.

I would not be situated to verify but also adding the information about this book, not as advert but including picture and recommendation where to buy it, would be beneficiary for the wikipedia article. well, technically it would be an advert, whatshowever, "adverts" are required techniques and skills in the business of electronics. I wrote once, you'll have to invest at least $2000 to do anything meaningfully, and now, would rather say,$5000.

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#### Geno03245

##### New Member
Thanks nike6. As you noted on my site, waterheatertimer.org, it says "to save you time, I will also sell parts."

The site lists in detail all parts needed to install your own water heater timer > including identifying numbers > and the site lists where you can buy those parts. But some people live in small towns and have no local electric supply house.

At no point does my site say that selling parts is a primary goal or that a profit of any sort could be generated. I am a retired house painter, not a predatory profiteer.

I am offering a self-help way to cut 6-8% off the energy bill of every home that uses hot water heaters. I even lay out the mathematics to figure the savings.

6-8% is substantial for some people. Spread across entire countries, it becomes a staggering figure.

Forward-looking people are proposing positive changes for the future.

I am asking the electronic community for assistance cutting energy costs. A succinct and related response to my original inquiry is appreciated.

#### nike6

##### Banned
I see.
Yes also the site has some .ORG type information, non-profit tips (for free) to save energy.

I think it is a good website but was not sure if it is a non-profit organisation, or a webshop.
there are (in the U.S.) many government funded organisations which are using .ORG

What i want to say is that there is no rule about non-profit, but the majority of .ORG sites are maintained by such organisations.

correct me if I am wrong...

I always search for "About us" background info, if there is not it, sometimes I do not sign up for such sites.

edit: I have looked, there is a good "About us" disclaimer, i just did not see it on the first visit.

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#### Geno03245

##### New Member
Thanks MikeMI

I'll read up. I ordered a couple beginner 555 kits in effort to learn the basics. Ordered a couple beginner electronics books via amazon. Hope to stitch something together in next couple months and let this site look it over and tell me why it doesn't work.

#### Geno03245

##### New Member
nike6,

I am absolutely new to websites. The service that sold me the domain name advised me of the .org issue and added that there was no 'hard-n-fast' rule > but generally I am offering straight-out self help.

in your 1:43 response, you mentioned a book, but I don't see the title > please repeat title when u got a moment

Thanks

#### Geno03245

##### New Member
nike6

IC555 Projects by EA Parr > see it now

#### nike6

##### Banned
Geno03245,

being an internet activist a little, that was also the thought I had: "there is no hard-and-fast rule".

the book title is "IC 555 projects", it is a classic.
I'd also recommend the (old) CMOS cookbook from Don Lancaster,
and to look up his web domain: Don Lancaster's Guru's Lair

the graphics on your website are a bit scary especially the "ji-had type mask wearing guy on the TV screen". most Americans are afraid of them, would say.

I'd recommend also to establish a .COM domain for the commercial part of your website, and crosslink them.

the attention span of many web visitors is just a moment maybe 2 seconds.

#### Geno03245

##### New Member
nike6,

Thanks for the title. I have a lot of studying ahead.

Yes, 2-second internet attention span > but rather that than locked down by 150 tv channels void of innovation for 50 years

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