I need a circuit made for me. I will pay you for it - Page 5

bradleyk · 12th May 2012, 8:08 AM

the trim pots have 25 turns,there should be a hard stop at each end

davidb2012 · 12th May 2012, 8:19 AM

Quote:

Originally Posted by bradleyk

i have had some luck with my gas, im not too sure, i just use what ever solder i have lying around, i'd say i'm not very good tho do you know how small it is?

look at page 15
http://www.allegromicro.com/en/Produ.../1391/1391.pdf

board:
using the easy one, as my version of eagle doesn't have the small one.
pix

that is 60x16mm

On the PCB drawing what is the box on the far left with a backwards Q1 on it?

davidb2012 · 12th May 2012, 8:20 AM

Quote:

Originally Posted by bradleyk

the trim pots have 25 turns,there should be a hard stop at each end

Thats what i thought but it never stops???

davidb2012 · 12th May 2012, 8:23 AM

Looking at them i think they make a slight click once their at the end.

bradleyk · 12th May 2012, 8:34 AM

Quote:

Originally Posted by davidb2012

On the PCB drawing what is the box on the far left with a backwards Q1 on it?

that is a mosfet

do you have a multi meter?

davidb2012 · 12th May 2012, 8:45 AM

yeh somewhere i will dig it out. where should i measure?

davidb2012 · 12th May 2012, 8:50 AM

So do i need the mosfet as it isn't in my circuit. A mosfet is just a transistor right?

davidb2012 · 12th May 2012, 9:12 AM

Between pin 1 and ground there is 1.8V but between pin 7 and ground it is 0V. at the LED it is 1.5V but no light???

The batteries are ok at 3V

davidb2012 · 12th May 2012, 9:18 AM

Hall effect sensor is at between output and ground is 1.5V put a magnet up close goes to 0V turn the magnet round goes to 3V.

Just looking at the specs of this hall effect sensor and it says operating voltage is 4.5V to 6V

I only have 3V input maybe this could be the problem?

bradleyk · 12th May 2012, 9:21 AM

Quote:

Originally Posted by davidb2012

So do i need the mosfet as it isn't in my circuit. A mosfet is just a transistor right?

the mosfet is for later, for the solinoide, it is similar to a transistor

Quote:

Originally Posted by davidb2012

Between pin 1 and ground there is 1.8V but between pin 7 and ground it is 0V. at the LED it is 1.5V but no light???

The batteries are ok at 3V

pin 1 and 7 should never been on at the same time, 1.5 is a bit low, remove the resistance. from the led.

Quote:

Originally Posted by davidb2012

Hall effect sensor is at between output and ground is 1.5V put a magnet up close goes to 0V turn the magnet round goes to 3V.

Just looking at the specs of this hall effect sensor and it says operating voltage is 4.5V to 6V

I only have 3V input maybe this could be the problem?

the hall effect seems to be working fine, as the output is changing, also measure the voltage on the led, try to make it go to 0, by adjusting the pots.

with no magnet, the the voltage at pin 3 should be at less voltage at pin 2 and pin 6 should be higher then pin5

Odje · 12th May 2012, 9:44 AM

Quote:

Originally Posted by bradleyk

the mosfet is for later, for the solinoide, it is similar to a transistor

The T in MOSFET stands for transistor, so it is a transistor.

davidb2012 · 12th May 2012, 10:06 AM

ok well some good news. Technically the circuit works. across the LED i have got to 0V then when i introduce a magnet either pole it jumps to 1.5V, when the magnet is removed it goes back to 0V SUCCESS however the LED still doesnt light and i have replaced the last resistor with wire.

One pole of the magnet works at 2.5cm away and one pole works at 9cm away.

Iv just checked the LED doesn't light up with 1.5V direct it needs at least 3V so we do have a working circuit. Now do you think we maybe need more power? If we have to then i suppose we will have to fit it in. Maybe 4AA's or 3AA's what do you think. Also how do we get the distance further as eventually the hall effect sensor will be behind 2mm of PVC.

Oh i tried with that small sensor and it was practically impossible

RussellK · 12th May 2012, 10:08 AM

Quote:

Originally Posted by Odje

The T in MOSFET stands for transistor, so it is a transistor.

And I hope you'll be gifting it with a flyback diode before connecting it to a solenoid...

davidb2012 · 12th May 2012, 10:14 AM

pins 2, 3, 5 and 6 are all 1.5V with and without magnet

bradleyk · 12th May 2012, 10:25 AM

i have to get to work ,i can make a pic when i get back about 3 ish

12th May 2012, 8:08 AM	#61
bradleyk Member Join Date: Nov 2009 Location: Canberra Posts: 201	the trim pots have 25 turns,there should be a hard stop at each end __________________ susessful trades reaperoflife ,V1C7012 , nrzln ,sanjay ,Kenny3011 ,Heatpipe ,hankahanaka ,smackus ,Oblivion-330 ,Kow ,shonofear , reflextion ,Big Daddy ,achimw ,j00cy ,ECHO ,sirelliottm, willisss 2,autumn21, BevanMx5, brendohall, gnasher666, , cmdwedges, 1shot1kill, rowen, Xeon666, reflextion, friedsweasel, krimnl 2, gbtaufae, wast3gat3, adktz, edr34, xsphera, CD, damike, Mjollnir, jowjeh, ScrumpyJim, kambo_rambo, ~kraven, Oppressa

12th May 2012, 10:25 AM	#75
bradleyk Member Join Date: Nov 2009 Location: Canberra Posts: 201	i have to get to work ,i can make a pic when i get back about 3 ish __________________ susessful trades reaperoflife ,V1C7012 , nrzln ,sanjay ,Kenny3011 ,Heatpipe ,hankahanaka ,smackus ,Oblivion-330 ,Kow ,shonofear , reflextion ,Big Daddy ,achimw ,j00cy ,ECHO ,sirelliottm, willisss 2,autumn21, BevanMx5, brendohall, gnasher666, , cmdwedges, 1shot1kill, rowen, Xeon666, reflextion, friedsweasel, krimnl 2, gbtaufae, wast3gat3, adktz, edr34, xsphera, CD, damike, Mjollnir, jowjeh, ScrumpyJim, kambo_rambo, ~kraven, Oppressa

12th May 2012, 8:23 AM	#64
davidb2012 New Member Join Date: May 2012 Posts: 53	Looking at them i think they make a slight click once their at the end.

12th May 2012, 8:45 AM	#66
davidb2012 New Member Join Date: May 2012 Posts: 53	yeh somewhere i will dig it out. where should i measure?

12th May 2012, 8:50 AM	#67
davidb2012 New Member Join Date: May 2012 Posts: 53	So do i need the mosfet as it isn't in my circuit. A mosfet is just a transistor right?

12th May 2012, 9:12 AM	#68
davidb2012 New Member Join Date: May 2012 Posts: 53	Between pin 1 and ground there is 1.8V but between pin 7 and ground it is 0V. at the LED it is 1.5V but no light??? The batteries are ok at 3V

12th May 2012, 9:18 AM	#69
davidb2012 New Member Join Date: May 2012 Posts: 53	Hall effect sensor is at between output and ground is 1.5V put a magnet up close goes to 0V turn the magnet round goes to 3V. Just looking at the specs of this hall effect sensor and it says operating voltage is 4.5V to 6V I only have 3V input maybe this could be the problem?

12th May 2012, 10:06 AM	#72
davidb2012 New Member Join Date: May 2012 Posts: 53	ok well some good news. Technically the circuit works. across the LED i have got to 0V then when i introduce a magnet either pole it jumps to 1.5V, when the magnet is removed it goes back to 0V SUCCESS however the LED still doesnt light and i have replaced the last resistor with wire. One pole of the magnet works at 2.5cm away and one pole works at 9cm away. Iv just checked the LED doesn't light up with 1.5V direct it needs at least 3V so we do have a working circuit. Now do you think we maybe need more power? If we have to then i suppose we will have to fit it in. Maybe 4AA's or 3AA's what do you think. Also how do we get the distance further as eventually the hall effect sensor will be behind 2mm of PVC. Oh i tried with that small sensor and it was practically impossible

12th May 2012, 10:14 AM	#74
davidb2012 New Member Join Date: May 2012 Posts: 53	pins 2, 3, 5 and 6 are all 1.5V with and without magnet