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Electronics => Projects => Topic started by: hogar on December 13, 2008, 12:46:14 00:46



Title: Optical switch help
Post by: hogar on December 13, 2008, 12:46:14 00:46
Help me with the following:

I am using rubber carrier to the full in a bag granulated food . I need devices when bag reaches certain weight to turn off carrier, but that it starts again only when manually restarts.
Pulse from the weight scales I made using infrared sensors but when lift the bag sensor send signal again end carrier starts again.

   
My English is bad,      
i hope that you understand me


Title: Re: Optical switch help
Post by: pickit2 on December 13, 2008, 01:15:16 01:15
A drawing of what you have now, would be a start. I see you don't know pic chip, but you could do it with switchs /or and/ relays.
A push switch to start, when bag is full, relay removes power to start, till it is reset.


Title: Re: Optical switch help
Post by: Parmin on December 13, 2008, 04:06:01 04:06
you need a "ONE SHOT" switch with latch and unlatch switching function.

Search google for ONE SHOT SWITCH


Title: Re: Optical switch help
Post by: DTiziano on December 13, 2008, 10:04:01 22:04
I hope the annex circuit can help you found the solution.
It is a classical circuit to start/stop a relay.
The first normally closed switch must be driven by the weight (open= at weight reached)
At power on K1 is off.
Pressing the manual start push button energize the relay coil, K1 contact close and keep it ON.
At weight reached, the top switch open, stopping K1.
Use start button to restart again.
Of course, the rubber carrier (motor) must be driven by some additional K1 contacts.


Title: Re: Optical switch help
Post by: hogar on December 14, 2008, 12:00:06 00:00
I have done so far following:   
Relay contacts are closed(relay is on) until between the diode and the transistor is no obstacle(the rubber carrier running)when weight reached (obstacle betwen sensors)relay is off.
But when lift up the bag ,obstacle are removed and the carrier starts again.


Title: Re: Optical switch help
Post by: newboy on December 14, 2008, 07:39:23 07:39
hogar,

You can put a SCR between +12V and emitter of BC327. The gate of SCR, you connect it to +12V through a switch.

If u can attach your  schematic (if u make it using eagle) then I can modify it for u.

Hope this help.



Title: Re: Optical switch help
Post by: hogar on December 14, 2008, 10:21:41 10:21
Thank you for your trouble, here is
scheme in eagle 4.16


Title: Re: Optical switch help
Post by: newboy on December 14, 2008, 10:48:53 10:48
Thank you for your trouble, here is
scheme in eagle 4.16

Here you are.

Please try it. If not function, let try to change the value of  R6. For the SCR1, you can use any SCR that can supply enough current/volt for your relay.

Hope you can share the result .. is it ok or not ?




Title: Re: Optical switch help
Post by: hogar on December 14, 2008, 12:12:20 12:12
    
   
Of course that will be shared, but only tomorrow can try.

Thanks


Title: Re: Optical switch help
Post by: hogar on February 16, 2009, 10:40:44 22:40
   
I tried function its working ,   
Sorry about delay


Title: Re: Optical switch help
Post by: newboy on February 17, 2009, 06:43:58 06:43
Glad it's working ...  ;D


Title: Re: Optical switch help
Post by: Jehan on February 19, 2009, 04:41:55 16:41
best is to use a monoshot using a 555 ic, 


Title: Re: Optical switch help
Post by: newboy on February 20, 2009, 05:45:13 05:45
best is to use a monoshot using a 555 ic, 

Any schematic example ?


Title: Re: Optical switch help
Post by: hogar on February 28, 2009, 08:26:49 20:26
I'm short with time but
(I work in emergency in shift) i'm gona try soon
Thanks guys    
of interesting.......