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1  Using Arduino / Project Guidance / Re: Reading a current transformer on: Today at 03:30:49 am
Hi,
Quote
the VSD will do everything right and protect itself and the motor first, before listening to the input from a control signal.

Exactly.

Also the VSD may have an output already setup to represent motor current.

Tom........ smiley
2  Using Arduino / Project Guidance / Re: Reading a current transformer on: August 19, 2014, 09:40:05 pm
Hi what type of VSD is it that you want to interface with brand, model?
I think you want to read the 4-20mA output that outputs drive current, and get the arduino to output a PWM (which you will have to conditon to get variable DC) to throttle back the drive to keep max possible RPM without overload.

What you will have to be careful of is;
1) the reason for the current going to overload is an increase in load.
2) an increase in load will cause the motor to heat up.
3) slower motor means less cooling (unless it has a separate cooling fan)
4) motor gets hot, possibly too hot.
5) the VSD may have other ideas about what you should be doing.

Tom...... smiley
3  Using Arduino / Project Guidance / Re: Improving Performance of 'void loop()' on: August 19, 2014, 09:30:01 pm
Hi what does your program do that makes it sensitive to loop time?

Tom.... smiley
4  Community / Bar Sport / Re: Music & Electricity on: August 19, 2014, 04:54:40 pm

Ohm my God, that was bad. Watt made you tell that joke?

5  Using Arduino / Project Guidance / Re: Knock lock reset on: August 19, 2014, 04:15:12 am
Hi, please explain what your project is and what it is doing, also a picture of your project would help too.

At the moment we have no idea of what your problem is or what you are trying to achieve.

You have to regard us as people who have never heard of your project and no nothing of how it works.

Tom...... smiley
Also please do not double post your requests.
6  Using Arduino / Project Guidance / Re: Problem controlling servos with joystick on: August 18, 2014, 09:40:22 pm
Hi, the problem you have is that you are relying on one fixed value from the joystick to be always the mid position, as you have found this is not the case.
You will have to program in a bit of code that will stop servo output if the joystick x and y inputs are within a certain range of values, it called hysteresis.
If on the x axis, full left is 0 input and 1023 is full right input then 512 is mid point but only if joystick is perfect.
You will have to add code that from say 504 to 520 input is centre and no servo output occurs.
504 to 520 is only a suggestion.
And do the same for the Y axis.

Tom...... smiley
7  Topics / Robotics / Re: Unable To Use Multiple Servos On Arduino on: August 18, 2014, 09:21:50 pm
Hi can you post a picture of your project and a CAD or picture of your circuit in jpg, png or pdf format please.

Tom.... smiley
8  Using Arduino / General Electronics / Re: Temperature sensor works with usb power, but does not when powered by wall plug on: August 18, 2014, 04:05:23 pm
Hi,do you have a DMM?
You need to measure voltages around your project to check for problems.

Tom..... smiley
9  Using Arduino / Programming Questions / Re: Sensor Reading/Arduino/Coding/ on: August 18, 2014, 04:58:34 am
Hi,

http://www.farnell.com/datasheets/51633.pdf

A LV 25-P is a voltage transducer, allowing you to measure DC,AC and pulsed voltages with galvanic isolation.

Tom.... smiley
10  Using Arduino / General Electronics / Re: LM324 output to Arduino interrupt not working correctly (with schematic) on: August 17, 2014, 04:32:27 pm
Hi, have you looked at the data sheet, in particular the  part on page 17 about interference and bypassing the AD623 at the power supply pins.

http://www.analog.com/static/imported-files/data_sheets/AD623.pdf

Can you please post a copy of your sketch, using code tags.

Tom..... smiley
11  Using Arduino / Motors, Mechanics, and Power / Re: Proportional Valve Control on: August 17, 2014, 08:44:49 am
Hi, if you can get the PWM down to 22Hz, it should be fine, any higher and you will have control problems when it comes to getting the valve to open smoothly.
The impedance of the coil will limit the current flowing through it, hence how much magnetic  energy is being exerted on the valve spindle.

Tom..... smiley
12  Using Arduino / Motors, Mechanics, and Power / Re: Proportional Valve Control on: August 17, 2014, 02:17:44 am
Hi, I think you will first have to look at the proportional valve specs, it specifies a -3db response to PWM as 22Hz.
The arduino PWM, UNO is

Quote
Note that the base frequency for pins 3, 9, 10, and 11 is 31250 Hz
Note that the base frequency for pins 5 and 6 is 62500 Hz

This page will give you how to change the PWM.

http://playground.arduino.cc/Code/PwmFrequency

The controller they recommend does a lot of things to drive your valve, including linearising the flow response and one of the most important things, control current. You are working with an inductor, AC current, not just an on=off switch pulling an inductor, impedance is now in play.


Tom....... smiley
13  Using Arduino / General Electronics / Re: Temperature sensor works with usb power, but does not when powered by wall plug on: August 17, 2014, 01:09:48 am
Hi, measure the 9V input when your have it connected, see what the voltage goes down to.
I'd say you wall plug id typical and is not a regulated supply.

Tom.... smiley
14  Using Arduino / Programming Questions / Re: Voltage read circuit with relay on/off on: August 16, 2014, 11:57:20 pm
Hi,
Please use code tags.. See section 7 http://forum.arduino.cc/index.php/topic,148850.0.html

Can you please post a COMPLETE copy of your sketch, using code tags.

When you get these discrepancies, can you measure the voltage at the analog input pin of the arduino as well, PLEASE.

1) Where is your battery?
2) Can you post a COMPLETE circuit diagram, including, solar panel, solar controller, battery, arduino, relay and pump.

Tom....... smiley-eek
15  Using Arduino / General Electronics / Re: Old Computer Power Supply on: August 16, 2014, 11:22:05 pm
Hi.
http://www.dslreports.com/faq/9208

black and green?


Tom.... smiley
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