Light activated label dispenser

Bernard

Joined Aug 7, 2008
5,599
OP is still looking in so here are my final thoughts:
FET, IRF520, 100V, 8A, .3 ohm or similar; Slot interrupter, ON1102, CNZ1102, IR LED 50 mA , - transistor sensor 20 mA @ 30V. or similar.
I would put a 2 ohm resistor in series with motor to limit peak current @ 10W , assuming intermittent use.
 

Bernard

Joined Aug 7, 2008
5,599
We can use a 555 IC timer to give a comparator for optical slot switch output. Only the IR LED current needs to be adjusted, in test 470 ohms
, which gives 5V @ pin 6 with backing & label in slot, just backing in slot gives 11 V, resetting 555.
Bowled a 205 this morning, ave. 135.Label  Control 00000.jpg
 

Thread Starter

gerstley

Joined Nov 20, 2015
58
I am back to working on this project and had a question.
I would put a 2 ohm resistor in series with motor to limit peak current @ 10W , assuming intermittent use.
Looking at your sketch, I see a 2 ohm resistor on the control circuit branch. Should I have another 2 ohm resistor before the motor? I am ordering parts and will give this a try once they arrive.
 
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Bernard

Joined Aug 7, 2008
5,599
Welcome back. If you already have the speed control then 2 ohm not needed. No 2 ohm in input, maybe 2 is pin number on 555? Radio Shack may still have matched set of IR LED & photo transistor, 276-142. Most slot detectors are not very deep so might have to make your own.
With another 555 you could add a time out circuit to stop motor if it ran for more than 1 or 2 labels?
With a second set of sensors, label could automatically
advance when a label was removed?
Do you have a new sketch?
 

Thread Starter

gerstley

Joined Nov 20, 2015
58
There is a 2 10w resistor showing on your sketch near the motor. I have the speed control so I will just leave the resistor out. You are right, the slot detectors are not very deep. I was going to use this led: https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&catalogId=10001&productId=1950825
and this photo transistor:https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&catalogId=10001&productId=2120410
Would they work?
A time out would be good but would a second press of the on-switch stop the motor? If so, that would work for me.
 

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Bernard

Joined Aug 7, 2008
5,599
A better match for photo transistor might be Jame Co PN: 372737, 880 nm, 10 degree, mfg. # UT1883-81-880-R.
A 90 deg. bend over 1/8 in radius peels a label edge reliably. Take up drum capacity needs to be almost the same size as supply.
More thoughts tomorrow, too many power outages today & then was blocked from AAC..
 

Bernard

Joined Aug 7, 2008
5,599
Modified plan: Would use # 12's pinch rollers to pull backing through to dump in a waste basket. A large spool for take up might be difficult to load & take out. & would vary speed on filling. D is a free floating idler, wood roller or maybe a small can of peas @ 8.5 oz. C is wood or another can of peas, empty with bearings & lid soldered back in.( Bearing could be brass tube soldered to end plates with steel shaft threaded on each end for nuts.) . For label spool holder,F, might use another can, Kroger mandarin oranges,10.5 in. 3 in. dia. X 3.25 in long nice fit on my spool. Nut on shaft to fit in slot on sides.
Automatic advance will work if in removing label, the backing does not advance until label is removed. The way that I envision it working, label gap passes over sensor J-K and may coast a bit, 1/4 in.?, but not detected by H-K. When label is removed, H-K activated & motor advances label to next gap & stops. A larger gap between G & L makes label removal easier but makes sensing between H & J more difficult. A label advance switch is also available as is a kill switch.Label  Dispenser 00000.jpg
 

Bernard

Joined Aug 7, 2008
5,599
Some sensor thoughts: The label backing is a good light diffuser so it helps to keep backing just a few mm from photo transistor. Last test was with a red laser diode module @ 15 mA & unknown SMT broad band photo transistor. Label & backing 4V, output just backing 800 mV.. Laser spacing inches to feet. Lased tested similar to Jameco 2120428 or 2217692.
It will take two lasers unless gap detector IR LED is placed close to label on separate support.
Photo transistor used with existing 1 M collector to + 5 V supply, emitter _ supply, readings from collector.
 

Thread Starter

gerstley

Joined Nov 20, 2015
58
I have ordered the Jameco ir led (#1950825) and photo transistor (#372737). I can position them very close to the paper. Are they unlikely to work? I have constructed the dispenser pretty much as shown in the drawing I posted and have been testing it with the motor and speed control. It seems to work pretty much how I want it to. My basic needs are to have the circuit stop the motor when a label gap is seen and to have the motor start when a momentary on button is pressed (I am thinking to use a foot switch). It would be nice to have the button set up so a second press would stop the motor if the detector fails to spot the gap.
 

Bernard

Joined Aug 7, 2008
5,599
This circuit may work as you requested. Added a 4011 quad 2 input NAND IC & a few Cs & Rs..At power-up Q6 -3 should be low , inverted by Q4 giving a hi on Q2-1. If SW-1 is pressed Q2 will have both inputs hi, output ,p-3, goes low triggering Q6, Q6-3 goes hi. The low on Q2-1 blocks SW1, & enables Q3 after a short delay which prevents Q6 from oscillating. If the gap is not detected, operator can press SW1 again , causing Q3-10 to go low, resetting Q6 stopping motor. Not bread boarded but should work. Comments welcomed.Label  Dispens 2 00000.jpg
 

Thread Starter

gerstley

Joined Nov 20, 2015
58
The speed control and motor are separate items. The speed control has 2 screw terminals for power and 2 for the motor.
 

Thread Starter

gerstley

Joined Nov 20, 2015
58
Thanks for the updated circuit diagram. It looks great! I have parts coming and should try putting it together next week. I have ordered a digital counter to keep track of how many labels are dispensed. http://www.ebay.com/itm/291250763941
Would I take a signal for the counter just before your resistor R8? Also, there is a diode shown at the motor. What should I use for it?

I will have more questions when I start building it.
 

Bernard

Joined Aug 7, 2008
5,599
Q6-3 is proper signal for counter.
Motor as shown will only work if Power neg. & Motor neg. are common; measure with ohm meter.
If not common may need a relay to drive motor.
Motor diode any of 1N4000 family or similar, I stock 1N4002 & 1N4004.
 

Thread Starter

gerstley

Joined Nov 20, 2015
58
The motor controller has 4 terminals; power +, power -, motor+, motor -. When I connected power to the 2 terminals, I measured 0 volts between the 2 negative terminals (power and motor). Also, the motor runs with the motor negative connected directly to the power negative terminal. Does that answer the question?
 

Bernard

Joined Aug 7, 2008
5,599
See you in about 2 weeks.
If you encounter unsolveable electronic problems, I would supply a wired circuit board, probably wire wrap, for $ 25 .
Includes postage, box, terminal strip IC's & Q7. You supply IR LED & Q1 or as desired.
 

Bernard

Joined Aug 7, 2008
5,599
Last thoughts before I break it down & file it away: I put it on a breadboard using a LED to monitor output. Worked at power up.
As SW1 will be separated from circuit by maybe a foot, thought it adviseable to lower impedance of SW1 pulse by changing R6, 10k down to
300 ohms, +_ 20%. Same for R3-R4, might go as low as 10K if gap can still be detected. Use twisted pair for both SW1 & Q1
 
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