Lighted Hockey Puck

[DZ12488]

Could someone help me with a circuit that would power 4 - 20ma SMD LEDs that are turned on / off via latching hall affect sensor on circular PCB that will be preassembled and integrated into the hockey puck.

TO OPERATE :The consumer would hold a magnet with north pole in right direction to turn on the leds . Puck would stay lighted as long as the hall affect sensor is not introduced to pole reversing OR magnet presence.
To turn off he would orientate the poles in opposite direction and the leds would switch off.

The supply voltage will be a single large button cell 3v battery in a holder on reverse side of pcb. I was hoping that the circuit would use no power or very very little power when it is turned off . Shelf life is very critical here . Could any one come up with a latching low power consumtion schematic that would turn on the leds via a megnet held to the exterior of the puck. I am hoping to mass produce this product once it is tested for its power longevity .

All ideas submitted will be reviewed and tested .If there is a Schamatic I select as the best or suitable for my application, will recieve a reward of $20.00 USD ! (Must have PayPal account.) I will contact you if you are the winner! More than one design increases your chances of winning. Thanks!

 

[audioguru]

A 3V button (coin?) battery cell might be able to light ONE 5mA red LED dimly for a few minutes. You are talking about 80mA which will be impossible.
What about changing the weight of the puck? Messing up its balance (wobble, wobble)?
Will a plastic LED survive being hit by a puck or crashing into the boards?

For many years, Cmos logic ICs use almost no current when they are idling. Since your battery voltage is very low then 74HCxxxx logic ICs must be used. I hope you find a Mosfet that switches well with such a low voltage.

 

[tunedwolf]

What about including say a small shielded coil with an equally small magnetic plunger and counter weight/ spring arrangement type thing and rectify/ condition the output and use it to charge a supercap or something to elongate battery life, or if it could be made efficient enough, to actually power the device from being whacked around? Just a random thought...

 

[Wade Hassler]

Once you get enough battery, how about a tiny microprocessor that sits waiting at microamps of current-draw and periodically wakes up to check a Hall-sensor.
Or better yet, check an accelerometer, turning on the lights for a time during and after acceleration events.
If your sensor provides a trigger, you wouldn't even need the wake-up.

 

[ronv]

How long does it need to last?

 

[audioguru]

I have some 3V red LED chasers and some 6V bright blue and bright green chasers that I designed. I use very low power Cmos logic ICs. A 74HC4017 IC drives the anodes of the LEDs high and some logic gates drive a transistor that blinks the cathodes of the LEDs low for only 30ms to save battery power. The circuits chase around and around 3 times then pause for 2 seconds to save more battery power then the chasing begins again. AA alkaline battery cells last for 3 months.

Maybe you can also blink the LEDs for only a moment to save battery power. Maybe you can blink only one LED at a time to save more battery power.

 

[Gobbledok]

An energizer CR2032 button cell has a typical capacity of 240mAh, at which point the cell will be at 2V. At 80mA, the best case scenario is that you will get 3 hours from the battery.

Worst case scenario, your circuit will drop out well before 2V and the battery will not meet the rated capacity due to a (relatively) high current draw and the internal resistance of the battery. Maybe not even 1 hour?

You are probably better off using a AA battery and a DC-DC step up converter. A AA Battery will have a capacity of upwards of 1500mAh and be capable of much higher discharge rates.

 

[audioguru]

The datasheet for an Energizer or Duracell CR2032 lithium coin cell shows how weak it is. It has a 240mAh capacity when its current is only 0.19mA (15k load).
Its internal resistance when new is 20 ohms so with a load of 80mA its output voltage will be 3V - (80mA x 20 ohms)= 1.4V for a few seconds which is not enough to light red LEDs.
With a load of 6.8mA it can be pulsed for 2 seconds, 12 times per day and its voltage slowly drops.

 

[Gobbledok]

The datasheet for an Energizer or Duracell CR2032 lithium coin cell shows how weak it is. It has a 240mAh capacity when its current is only 0.19mA (15k load).
Its internal resistance when new is 20 ohms so with a load of 80mA its output voltage will be 3V - (80mA x 20 ohms)= 1.4V for a few seconds which is not enough to light red LEDs.
With a load of 6.8mA it can be pulsed for 2 seconds, 12 times per day and its voltage slowly drops.

Ouch, way worse than I expected.

 

[crutschow]

You might try some high brightness type LEDs and see if they are bright enough at a few mA of current. If so you may be able to get by with a couple of the large button cells to light it for a reasonable time. Flashing the LEDs with a short duty-cycle pulse can also save significant power.

For turn on you could perhaps use a small accelerometer switch with a time delay to turn the unit back off. As long as the puck was being periodically hit the lights would stay on. After a period of disuse the time delay would turn the circuit off.

 

[dr pepper]

I have a led light on the wheel of my push hog, it has 3 leds, a controller chip and is powered by a cr2016 lithium cell, and it lasts for hours, your power source is sensible.
A pic10f200 microcontroller and a piezo cell is perfect for such an app, the puck would turn on for a period after its been smacked.
You would have to build the circuitry very robustly as you know it'll get a lot of stick, the battery holder would need to be screwed down.

 

[audioguru]

A little Lithium coin cell battery can blink an LED (one at a time) very brightly if the battery charges a pretty big capacitor then the capacitor powers the LED. The word "blink" is very important for long battery life.

 

[crutschow]

I have a led light on the wheel of my push hog, .....................

I probably shouldn't ask this but what's a "push hog"?

 

[dr pepper]

Push hog, push wreck and push iron are all northern uk slang for bicycle, sorry I should know people reading this are from all over.

 

[DZ12488]

Thanks you all,for the ideas Gtting back to some of u that had questions: The battery life should out last the puck and that might be being wacked around the rink for about 4hour shifts, I am guessing .. if it would last for at less 10 shifts I would say thats about the life of that puck any way .Leds take a beating ,but since they are in the center ,no
problem.I want this to be disposable and CHEAP. Cost in the components are critical.
had made these lighted hocky pucks with only 1 - 3v lithium battery , & very low ohm resistor that allowed only a few milliamp draw .
Switch was a set screw that connected the curcuit to complete the cycle . After a hour or so the puck lost connection and you had to turn the set screw in farther or throw it away . I had one lighted puck that lasted till the puck split into pieces. Weightwise is not an issue since the circuitry is all in the center and light tubes are going out from the leds on the board. clear filler is used around the led and light tube junction to keep black rubber compound from flowing in between the light tube and led. I was thinking of high speed pulsing circutry but could not come up with the hardware that would operate at such low voltages.Thats why I am asking for ideas.
Remember these are disposables and not repairable. My old curcuit used high brightness leds and used a resistor that limited the current draw to lenghten the bettery life. I need a smd curcuit that turns on and off without a mechanical sw. inside or outside of the puck also takes little to no current draw when on the shelf.

 

[audioguru]

Maybe you should find a night time blinking LED product made for a "push hog". See if it has a small battery that lasts long enough and is bright enough then copy it.
How about kids shoes that blink LEDs at night with each footstep?

Now I am talking about seeing the LEDs blink in the dark. Will the hockey games play in the dark?

 

[crutschow]

TI has some low voltage logic that works down to 1.8V. Perhaps that would work for your requirements to make a blinking circuit.

 

[DZ12488]

Hah, no the hockey game play in the darkness ,BUT their lighting is not the lighting as in a commercial facility or NHL rink . For the goalie , it is a very big benifit and lot of teams in my area like them and pay extra cash for these lighted pucks . I like your idea and I might see what I can find in blink curcuits.
I am currently working with a low op voltage hall affect sensor part# BU52040HFVCT-ND and 754-1519-6-ND LEDs & KSC1623LMTFCT-ND transistor and SMD resistor RMCF series from digikey

 

[dr pepper]

A cr2032 has 220mAH capacity, if you run a pair of leds at 20ma thats 40ma drain, so a single cell would last 220/40=5 hours, probably acceptable for the puck, 4 leds would be half that at 2.5 hours, might be long enough.
To increase capacity and run time you could use 2 cells, wire them in parallel, or if thats impractical wire them in series, but then you'd need some circuitry to efficiently reduce the voltage to the leds, but if your going to use some led driver logic that might be easy to do.

 

[audioguru]

A cr2032 has 220mAH capacity, if you run a pair of leds at 20ma thats 40ma drain, so a single cell would last 220/40=5 hours, probably acceptable for the puck, 4 leds would be half that at 2.5 hours, might be long enough.

No.
A CR2032 is a weak little battery cell. See my post #8 or look at its datasheet.