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switching ON a 12Vdc motor for 15 seconds every day at a specific time

switching ON a 12Vdc motor for 15 seconds every day at a specific time

switching ON a 12Vdc motor for 15 seconds every day at a specific time

(OP)
Hi guys,
My problem is that i have a motor that needs to be turned ON once, every day at a programmable time and for a duration of 10-20 seconds. The power of the motor is bellow 80W.
I have searched throught the net on Merlin Gerin, Schrack and similar catlogues but can't find any programmable time switch that can run in a pulse mode and also on 12VDC (i have a batterie that has to drive the motor and the timer). Usually they have those time switches on 230Vac but i need 12Vdc... Can somebody help me??

To conclude - the facts:
- 12Vdc power supply
- once a day at a specific programmable time to turn ON the motor
- power of the motor is bellow 80W and it is running on 12Vdc also
- duration of the pulse is between 10 and 20 seconds
- it needs to be as simple as possible (in order to be also the cheapest possible)
- it needs to be ready build - not a diy thing (maybe something similar to this:  http://www.hugo-mueller.com/weekly-time-switches/mueller-sc-08-11-paladin-172-110,p,en,1,1.html  )

thank You very much for any help You can give me
best regards
sunny
:)

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

(OP)
that is the problem...
we need to fix the motor control unit that is damaged now... it is using 12Vdc and the motor is also 12Vdc... also i have only a car battery to do the job....

the control unit has been modified - it is a normal 230Vac programmable time switch that you can plug into the main power outlet like in your houses, to control, for example, a water pump for your pool. The time switch has 1 minute as a shortest time you can set. So, the modification was to shorten that time even more using NE555 chip... it was working, but it was poorly made... what i would like to do is to make it with proffesional, ready made parts... like timers that can do that... the last option is to build another of these that we were using allready because they are not reliable....
i have found a timer and a turn ON delay... but the problem is to find these things running on 12Vdc... it is a real problem....

 

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

That's a good suggestion Bill.  Motor would probably work fine too, on that short a duty cycle.

0505975; Is this a one-off or a bunch of them?

Examples:http://www.omega.com/ppt/pptsc.asp?ref=PTC-14&Nav=autm02

http://www.omega.com/ppt/pptsc.asp?ref=PTC-12&Nav=autm02

http://www.borggeneral.com/digital-timer-series8842.html

http://www.factorymation.com/s.nl/it.A/id.765/.f

Keith Cress
kcress - http://www.flaminsystems.com

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

(OP)
heheheh.... thanks for the answers...
BUT...
i can't use link no. 1 and 2 because those are timers - not clock's ... i need a regular clock that will turn the motor ON each day at exactly 6:00PM (for example) and turn it OFF 15 seconds later.... and timer can't do that... i need to adjust the time when it needs to turn ON and OFF... and the time when the motor is turned ON needs to be between 10-20 seconds adjustable... that is what i need...

so link no 3 would be good BUT it has a minimum time setting of 1 minute and i need less....
so something between the link 3 and link 4 will be just right. ... if you look at the datasheet of the link 4 device here:
http://factorymation.info/relays/821TD10H-UNI.pdf

you can see on the page no. 2 the diagram A that is telling exactly what i need....but in one device...
on diagram A you have a clock that is making an impulse and a turn on delay shortens that impulse to just 10-20 seconds...
and what i need is one device that is doing just that...
when the time comes - it turns the motor on and after 10-20 seconds it turns it off again.... and everything should run on 12Vdc.....
 

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

Once again, microautomation comes to rescue. The LOGO! from Siemens can work off 12 V DC and has a built-in clock (and calendar) so you can make exactly what you want. You can even make it do exceptions for special week-days (if you want to).

The order number for the 12 V DC version is
6ED1 052-1MD00-0BA6

It is fun and easy to use and you can do much more than just turning a motor on/off with it.

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

(OP)
thanks for the answer...
it seems to me that LOGO is a bit complicated piece of equipment for such a simple job....
what is the price of the LOGO unit???
 

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

It is not complicated. It is capable. And standard. And does what you are asking for. And costs less than most timers. We use it all the time for lots of simple tasks. Cost is less than USD 200. What price range did you ecpect?  

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

If you are running total loss on this battery you will need to be concerned with the power consumption of the timer too.  So even if you manage to find one that works and costs 'right' it needs to also consume the right power!

A car battery is only good for about 65Ah so if the timer is not to kill the battery all by itself, in less than a week, you need it to draw less than 300mA or 3.6 Watts.

It's pretty amazing we can't find one that has a little microcontroller, an LCD, a realtime clock, some buttons, and a heavy duty relay in a nice little box...  It would probably draw less than 0.5mA.

I'm looking at a board in my hand that has everything in the list but the relay..

Keith Cress
kcress - http://www.flaminsystems.com

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

Buy an alarm clock with the 9 Volt backup option. Use the alarm to start the motor. Use a cheap timer to stop the motor after the set time.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

(OP)
@Skogsgurra - thanks for replying - i was looking at LOGO system - in my country it costs the double price for a real good quality timer (not the cheap ones for home usage but the industrial timers)... so it is not so cheap to use it - i try to target the total cost arround 100USD - that is why i need everything in one peace of an equipment.... because that way i will not need the clock , the turn on delay or something else....
i try to go cheap, ready made (if possible industrial) and reliable - i know i know... i am probably asking to much...
the interesting thing is that i have found the clocks that have but are running on 230Vac.... so i am even thinking on using a small inverter (inverter up to 20VA of power) to boost the voltage to 230Vac... this is also an option... i think that i might go with the inverter and a clock to a point of 100USD costs.... i have to check the timer prices i have found...
it is also a possible solution to use a clock that is turning on/off the bell in schools ... this one also might work on 12Vdc...
and i am thinking - a solar technologie is also running on 12Vdc and up.. i am thinking - is there not one piece of an equipment that will do the turning on/off a motor where you can use only solar cells and a car battery.... i am puzzled - very interesting that we can't find a ready made cheap solution .... i was even looking for a cheap chinese products... didn't found anything.... maybe those clocks exists but i can't find them.... that is why i turned to you guys...


@itsmoked - yes You are right - total consumption is also to be considered.... i am thinking on using a solar cells to do the job of cherging the batteries... but first i have to solve this timer thing.......

@waross - can you show me some of those - which alarm clock ??? cheap timer is usually for household and has to be optimized - i would like to have everything ready made - to have a finished thing looking proffesionally made .. not to diy things... i know how to make it diy... using NE555 and a cheap timer - but i would also like to avoid that... i am thinking that this solution might not be reliable enough - that is why i would like to go on a ready made product...


a question - how about a regular timer with a pulse mode that can run on 230Vac and power it with an inverter... can we find low wattage inverters - where - and also relatively cheap.... i am preety sure that 20VA would be enough... i found similar inverters in a car equipment - for converting car battery voltage to 230Vac for a notebook or something.... what is the consumption of that small inverter and where to find them... i can't find them small - like to mounted on a DIN rail or something... we have some dc/dc converters in our transformer stations for powering some electronic equipment - i am wondering - ther might be some dc/ac converters that are small.. any ideas...?

thanks for interest and best regards...
 

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

Forget the inverter..  Any inverter will draw, continuously, far too much power to work for you.

Keith Cress
kcress - http://www.flaminsystems.com

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

(OP)
that is what i was affraid....
that is why i didn't want to go for the inverter but right away on a 12Vdc power supply clocks...
but those are impossible to find....
man - this is a problem...
 

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

There is a very simple solution. Use the simplest PIC microcontroller with a 32768 Hz crystal. It will only draw between 15 and 20 microamps. Hook it up on a perf-board. Write a program that keeps track of time and switches on and off to your liking. It will not cost you even twenty dollars - including a decent relay.

Of course, that means that someone has to write the code. If you do it yourself and don't count your time (not a very wise thing to do), then you could have that function at a very low cost.

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

(OP)
Skogsgurra - i was thinking about that too.... the only problem with PIC is that when we want to change the time - we will have to change the program and write it again in the PIC... you can't easily chenge the time of the pulse... that is what's bothering me - and again - it is not ready made solution...
i am affraid that i might go after the PIC or a wallmart alarm clock afterall... those seems to be the only solutions....
if somebody has any other idea i would appreciate it - the rest of You guys that hepled here - thank You very much - You are realy great....
best regards
sunny :)
 

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

A "hybrid" where the 24 hour function is handled by the PIC and the pulse width by an analogue timer is probably the best way of doing it. You already looked at the 555, didn't you?  Then you can easily adjust pulse-width, without any reprogramming while the 24 h cycle remains unaffected.

I should know better than saying this: I can ask my SW guy to do the 24 h thing and put into an old rudimentary PIC if you want me to. But do not expect any support from us! Just a programmed chip and a note saying where the output pin is.

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

(OP)
no - gunnar - thank You... do not worry... i have here also a guy that can program a PIC so if i decide to do it with a PIC i will ask him to do it... thanks... :D
 

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

You deserve a star for that generous offer, Gunnar.
Yours
Bill

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

(OP)
for sure - the offer was extremely generous...
:D
 

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

And I am happy that you can do it on your own. I am not sure my guy would like that I give his work away. Even if it was an extremely simple task.

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

Gunnar you would probably wake up with a horse's head in bed with you.

Keith Cress
kcress - http://www.flaminsystems.com

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

(OP)
no - it is not a problem to do it - i just wanted to avoid DIY.... i wanted an industrial thing that looks nice and professional.......
o.k. - guys thanks for help... i know now that DIY is my only option... oh well :D
  

RE: switching ON a 12Vdc motor for 15 seconds every day at a specific time

(OP)
GUYS!!!!
it seems i've found it....

Hager seems to have such device.
on this link you can download the catalogue:
http://www.hager.co.uk/menu/downloads/2008-general-catalogue/modular-devices/3307.htm

and on page of the catalogue 4.10 you have a device that is called EG103V.. it is runing on 12/24V AC/DC and can be programmable to work in a pulse mode from 1s to 30min... this seems to be the thing i was looking for....
i have to contact Hager further to see if i am right....
:D
yeesss!!
 

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