MOSFET IRF540A circuit.

[CocaCola]

Never mind I sleuthed it out. The FET circuit you & CC posted are assuming the LED's cathode being pulled to GND,

He used a battery as a representation of the puck, ground would thus be the negative lead of the puck, not circuit GND... The transistors just act as simple switches to route the + out of the puck through either one or two LEDs to the - of the puck...

 

[CDRIVE]

Chris

I cant post the pdf as it 160K and it wont allow me to...
If you send me your email address I will email it

Justin

I think you missed my last post. Scroll up.

Chris

 

[JPU]

Never mind I sleuthed it out. The FET circuit you & CC posted are assuming the LED's cathode being pulled to GND, If you're going to use the uPuck as you've shown it in that jpg then I don't see how you can do it differently than I show here. As you can see you'll need 2 pucks.

2 Pucks!

They are £10 each

Are you sure!

Justin

 

[JPU]

He used a battery as a representation of the puck, ground would thus be the negative lead of the puck, not circuit GND... The transistors just act as simple switches to route the + out of the puck through either one or two LEDs to the - of the puck...

Yes, this is correct!

 

[CDRIVE]

He used a battery as a representation of the puck, ground would thus be the negative lead of the puck, not circuit GND... The transistors just act as simple switches to route the + out of the puck through either one or two LEDs to the - of the puck...

That's not how Justin has the puck configured. It's configured as I show it.

 

[JPU]

I just rolled out of bed, and I'm still rubbing my eyes but this is the short of it, use transistors not FETs...

T1 will turn on LED #1 & #2
T2 will turn on LED #2

See attached



Nope, not significant at all, the nA (or µA) draw is below the normal self drain of the battery in almost all cases... I have a device I built a year ago running off PIC16F684 that goes to sleep after 1 minute of no activity, it's running off 3 dollar store Zinc Carbide AAA batteries and it's still 100% functional after a year sitting on the shelf with frequent use... The batteries are holding out quite well...



Not quite sure where you are going with this, PICAxe breaks up the sleep command into three versions, there are SLEEP, NAP and HIBERNATE functions for the PicAxe (all variations of 'sleep'), you want to put the PICAxe into HIBERNATE (in PICAxe terms) in this case and wake it on a port change interrupt, not take a NAP or SLEEP for a period of time that conserves some energy but is not truly putting it to sleep...



Control it just like the LEDs from a pin on the PIC...

Its taken me a while,,,but yes this is simple.....

It should work

JPU

 

[CocaCola]

That's not how Justin has the puck configured. It's configured as I show it.

His clearly stated his circuit didn't work correctly, the series was only complete when both LEDs were enabled, not the one on then two on implementation he wanted, I corrected that in the layout I did so it worked as he wanted...

 

[JPU]

That's not how Justin has the puck configured. It's configured as I show it.

Chris,

If you PM your email address, I will send the pdf, turn to Page 4,,,,,that will show you how I configured it.



Justin

 

[CDRIVE]

2 Pucks!

They are £10 each

Are you sure!

Justin

If you're tying the LED anode to the + Output and the cathode back to the + Input, then yes. I assume you're using this configuration because it gives the widest Vin range. The puck doesn't have to be configured this way but that's what you posted in that jpg you copied from the pdf.

Chris

 

[CDRIVE]

Chris,

If you PM your email address, I will send the pdf, turn to Page 4,,,,,that will show you how I configured it.



Justin

Justin, did your doppleganger post this?

https://www.electronicspoint.com/attachments/4673d1340353497-mosfet-irf540a-circuit-toot.jpg

You posted it here...
https://www.electronicspoint.com/mosfet-irf540a-circuit-t249238p3.html#post1474507

 

[CDRIVE]

His clearly stated his circuit didn't work correctly, the series was only complete when both LEDs were enabled, not the one on then two on implementation he wanted, I corrected that in the layout I did so it worked as he wanted...

I'm not referring to the schematic he drew. See my last post.

 

[JPU]

Justin, did your doppleganger post this?

https://www.electronicspoint.com/attachments/4673d1340353497-mosfet-irf540a-circuit-toot.jpg

You posted it here...
https://www.electronicspoint.com/mosfet-irf540a-circuit-t249238p3.html#post1474507

Ok,,,,I got to slow down here!!

I have just got in, I have had 6 pints of the finest beverage the barman can draw, A fillet steak and a stunning Irish coffee and I feel that that you two guys are shouting hail marry's at me...


Chris,,you asked for the PDF,, I have only shown you a pic of it!.. I cant upload the rest as the file is too big.

I think what I have seen from CC might fit the problem, but I cant think straight.....(6 Pints) ??

Im off to bed with more electronic problems than this here [leaking personal information] can deal with!!

Ill catch up tomorrow..and leave you guys fight it out,,may the best guy win!

JPU

 

[JPU]

Ah ah Chris

I see your version ensures the micropuck is switched off when not in use!

Am I correct.

Justin.

 

[CDRIVE]

Ah ah Chris

I see your version ensures the micropuck is switched off when not in use!

Am I correct.

Justin.

Yes, but I've repeated myself to the point of core melt down. I enjoy the pub scene also so I'll let you sleep and read back over ALL of today's posts when your head is clear. Below are the three single puck configurations listed in the 2009 Applications pdf. The Buck/Boost Driver configuration is the one YOU posted.

2009 as a Boost Driver
2009 as a Buck Driver
2009 as a Buck/Boost Driver

Chris

 

[CDRIVE]

Justin, please post the LED model you're using. If you know what the forward voltage drop is post that too. It'll save me time digging out the data. It's late over here now so I'm going to hit the sack, but I wanted to post this schematic for you to ponder while I sleep. As you can see I used the Boost configuration as compared to the Buck/Boost config that you posted.

Chris

 

[JPU]

Chris

That looks great! I have a question.

I get the right hand side of the schematic but the left hand side is a little beyond me. How does the circuit switch off once on.

I have a PDF which I was sent via email and I dont think its on the LEDSUPPLY site, allthough you may have found it elsewhere. I'm not sure if you have access to this information as you would see the boost configuration has a max 3V input.

I have a dropbox account and I have placed the PDF there.
https://www.dropbox.com/s/h7o650izmnjfvln/MicroPuck.pdf

You can see that in your configuration the max input is 3V but we have a 3.7V battery, won`t this be a problem?

Am I missing something, I probably am.

Justin

 

[CDRIVE]

Justin, please post the LED model you're using. If you know what the forward voltage drop is post that too. It'll save me time digging out the data. It's late over here now so I'm going to hit the sack, but I wanted to post this schematic for you to ponder while I sleep. As you can see I used the Boost configuration as compared to the Buck/Boost config that you posted.

Chris

You haven't given me this yet. I need this information to properly select Z1. If you don't know then measure the output voltage of the Puck (your existing circuit) when you have both LEDs ON and wired in series. Z1 is a safety clamp that insures a load on the Puck's output while the Picaxe is waking up and shutting down.

Chris

That looks great! I have a question.

I get the right hand side of the schematic but the left hand side is a little beyond me. How does the circuit switch off once on.

I have a PDF which I was sent via email and I dont think its on the LEDSUPPLY site, allthough you may have found it elsewhere. I'm not sure if you have access to this information as you would see the boost configuration has a max 3V input.

I have a dropbox account and I have placed the PDF there.
https://www.dropbox.com/s/h7o650izmnjfvln/MicroPuck.pdf

You can see that in your configuration the max input is 3V but we have a 3.7V battery, won`t this be a problem?

Am I missing something, I probably am.

Justin

Yes Justin, as I repeatedly told you yesterday, I downloaded two pdfs for the 2009. If I repeat it one more time my head is going to explode. One of them is the Applications pdf that describes Boost Driver, Buck/Boost Driver & Buck Driver. Did you read back over all of my yesterday's posts???

Silicone Diodes have an inherent .7V voltage drop, so D1 insures that the input to the Puck will not exceed 3V when the battery is charged to 3.7V. There will also be a ,2V to .3V drop across the Emitter-Collector junction of Q1.

Chris

 

[JPU]

Chris

Don't let your head explode,,yet! I need you for this and the other project!!

I am charging a new 3.7V battery I have. As soon as its fully charged I will setup the circuit and measure those voltages for you.

Regards

Justin

 

[JPU]

Chris

I am going to show my real lack of knowledge here now...

If I put the negative of my meter onto the negative of the battery and the positive of the meter onto the 1st positiove of the LEDs (in series) I get 9.53V

If I put the negative of my meter onto the end of the run of LEDs ie the negative from the last LED and my positive onto the start of the run of LEDs ie the positive of the LEDs I get 5.51V

All this from the fully charged battery which I get 4.12V from.

Which Voltage is the relevant Voltage or do you need another.

Thanks

Justin

 

[CDRIVE]

Chris

I am going to show my real lack of knowledge here now...

If I put the negative of my meter onto the negative of the battery and the positive of the meter onto the 1st positiove of the LEDs (in series) I get 9.53V

If I put the negative of my meter onto the end of the run of LEDs ie the negative from the last LED and my positive onto the start of the run of LEDs ie the positive of the LEDs I get 5.51VAll this from the fully charged battery which I get 4.12V from.

Which Voltage is the relevant Voltage or do you need another.

Thanks

Justin

I wanted the measurement marked in red. It was needed to determine the Zener (Z1) voltage. Thanks for measuring it. Your fully charged battery voltage is higher than I anticipated so I'll be making some changes in the schematic.

FYI, I just came home from my pub but I suspect your Irish beer was better.

Chris