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1  Using Arduino / General Electronics / Re: HV multiplier on: April 09, 2013, 07:31:33 am
photo1 just shows the wiring after op-amp and before HVM.

When i attempt to put in a second voltage input it doesn't work, therefore i tried to test the circuit by building whats on photo 2, which works but the output is not ideal.
2  Using Arduino / General Electronics / Re: HV multiplier on: April 08, 2013, 09:35:30 am

I have built the buffer without the transistor system and the external secondary voltage input.
3  Using Arduino / General Electronics / Re: HV multiplier on: April 08, 2013, 09:15:55 am
When i connect up the circuit, it does not seem to work. I am inputting the output
4  Using Arduino / General Electronics / Re: HV multiplier on: April 07, 2013, 09:36:45 am
What i dont understand is, if there is a DAC, then hasnt the output become analogue? where does it turn dc again?
5  Using Arduino / General Electronics / Re: HV multiplier on: April 06, 2013, 04:40:54 pm
10-bit: 12-bit external DAC + possible op amp + emitter follower.

11-bit: 12-bit external DAC + possible op amp + emitter follower + 12-bit external ADC.

The "possible op amp" would be needed unless you are using the 5V version and it is lightly loaded.

When using a DAC, would that be connected to the Arduino output, and then to the rest of the circuit?
and im guessing the ADC will come before the HVM module? any examples on how to adjust the circuit, or what to add in to make these effective changes?

Also the op-amp i have, has 8 pins but only 3 is needed for the circuit (im presuming) but would i need to ground it too?

Also if another Arduino board was to be used (such as Due, which has a DAC) does that remove the need for an external DAC?

 
6  Using Arduino / General Electronics / Re: HV multiplier on: April 03, 2013, 07:17:59 am
1. You need a buffer because an Arduino can only supply 40mA per output pin, whereas the 5V version of the HV multiplier requires up to 250mA.

2. However, there are very few op amps that can supply as much as 250mA output current. That is why I suggested using an op amp and NPN transistor as the buffer.

3. You cannot connect the input of the buffer direct to an Arduino output pin, because the Arduino does not have an internal DAC to drive any output pins with a variable voltage, and you must not try to drive the HV multiplier with PWM. That is why I included the RC network at the input to the buffer.

Why can the HV not be driven by the PWM?

7  Using Arduino / General Electronics / Re: HV multiplier on: April 03, 2013, 06:03:37 am
This was the suggested circuit for using the HVM,
I dont understand why use a buffer?
8  Using Arduino / General Electronics / Re: HV multiplier on: April 01, 2013, 07:19:16 am


Also the resistor and transistor after the op-amp i presume is to control input voltage to the HVM?
9  Using Arduino / General Electronics / Re: HV multiplier on: March 31, 2013, 05:45:53 pm
Please explain the voltage requirements for the lense. Have you a specification or datasheet for the lense?

The +9V is where you connect the incoming power. You need to provide 9V or a little more at 250mA. You can use the same supply to power the Arduino if the supply can handle the extra current for the Arduino + anything running from its 5V supply.

The lens operates between 2-3kV, but we aim to be able to control it with a system.

Can the roles of the resistors prior to the op-amp and the role of the op-amp be explained in more detailed?
The resistors coming off the HVM i am assuming is to make safe the connection back to arduino ground?

(sorry im quite a beginner trying to attempt a complex project)
10  Using Arduino / General Electronics / Re: HV multiplier on: March 21, 2013, 12:22:35 pm
The transistor passes the power (up to 250mA) to the HV multiplier. The op amp cannot supply enough current by itself.

The high voltage output is on the right hand side of the schematic. The positive side is marked "+ 0-5 kV", and the negative side is marked Gnd. The negative side is common with Arduino ground. If you wanted negative output instead of positive output, then you would need to use model Q50N and change the arrangement of the voltage divider.

Okay my bad, what i meant was that the lense has to electrode probes that would need the voltage going to. Can this just be divided from the output? I dont understand the 9V at the top section either.
11  Development / Other Software Development / Arduino code for graphs on: March 21, 2013, 11:11:54 am
Hi, I am very new to Arduino and I am conducting a project where I will be controlling the magnitude of voltage going through a dielectric elastomer. This elastomer is material to build a lens, and the amount of voltage going through will determine how well it focuses. I have a model in Simulink that measures the focus parameter of a lens over time, this has been sent to a serial port i.e. in Arduino. When I connect Arduino to a voltage source, I need to get a graph of focus measure against voltage and then differentiate this graph to get the maximum. Is there a code in the Arduino library where I can do this? I know there is a 'Graph' code, will this allow me to get the variables I want in the graph?

Thank you
12  Using Arduino / General Electronics / Re: HV multiplier on: March 21, 2013, 11:09:56 am
The arduino will recieve data from matlab which measures the focus measure value from the lens. That part of the system has been done.
Depending on the value we need arduino to change the output voltage.

I still am unsure what the transistor does in the diagram.
Also the electro-optic lens needs the +/- ve connection, but on the diagram theres only one coming the hv multiplier.
13  Using Arduino / General Electronics / Re: HV multiplier on: March 19, 2013, 08:24:32 am
Here is a schematic for a possible solution. Since you still haven't said, I've assumed you are using the 5V version of the Q50 and that 8-bit resolution is sufficient. You will need to increase the PWM frequency if you want the settling time to be lower than a few seconds.

It is the 5V input version. Just checked.
8-bit is more than sufficient.

What coding specifically would go into arduino to control this?
14  Using Arduino / General Electronics / Re: HV multiplier on: March 18, 2013, 04:34:17 pm
No, I mean the input to the HV power supply. The Q50 is available in versions for 5V, 12V, 15V and 24V input. Have you chosen a particular model in the series, or is it flexible?



What I am asking is, what power supply do you intend to use to power the emco? The Arduino's 5V supply, or maybe some other power supply (such as your 10V power supply) which you may also be using to power the Arduino?

Currently we are running on the Arduino's 5V.
We do have an external power supply that we have not intended to use yet as there were issues with the board being unstable or overheating.
15  Using Arduino / General Electronics / Re: HV multiplier on: March 18, 2013, 01:26:18 pm
The input is variable, so it can be used via arduino or the external supply. Can you give me an example of an RC network model please? Also, are you referring to the actual setup of the system? Am I to assume that an RC network will be connected to an emitter and operational amplifier?

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