12v Cascade ( Powder Coating )

MisterBill2

Joined Jan 23, 2018
9,882
Here is picture of new gun with cascade inserted.View attachment 200634
Switching the power to the high voltage generation module using a 12 volt DC relay powered by the same power supply make more sense because relay is far more tolerant of any high voltage spikes that might happen. In addition, a relay is simpler to connect and mount, and does not require any electronic expertise to service in the event of a problem. And one of those automotive-type cube relays should serve very well. And a replacement would be available from many sources for many years to come. THAT is why I am suggesting using a normal electromechanical relay.
 

Thread Starter

Roger60

Joined Feb 29, 2020
34
Thank you again for your input.
The suggestions you are making are totally understandable, and simplicity is good. Is a relay just like a set of points on a car?
As they suffered at higher revolutions.
I did work on tv's many years ago at component level but didn't advance to further training as I took a new job.
All this studying has brought back a passion which I missed out on lol.
Your advice is genuinely appreciated and that is something I am very grateful for.
Since buying the cascade there's an accumulation of components which have appeared from somewhere.
Please continue to share your knowledge as it's far greater than mine.
Kindest regards
 

shortbus

Joined Sep 30, 2009
8,971
Switching the power to the high voltage generation module using a 12 volt DC relay powered by the same power supply make more sense because relay is far more tolerant of any high voltage spikes that might happen. In addition, a relay is simpler to connect and mount, and does not require any electronic expertise to service in the event of a problem.
The relay actually does two things in these, 1. put the power to the oscillator to make pulsed DC to the cascade, and 2. switches the air supply solenoid valve on. The guns at least the one I have, aren't like a paint spray gun, they have a solenoid valve to control the air.
 

shortbus

Joined Sep 30, 2009
8,971
Sorry Shortbus, I am computer illiterate, I thought you knew where I was from lol.(UK)
I have confused all as I didn't put up picture of my broken unit.
The cascade is what I purchased a while back and was only interested in using it because it was here with a new gun.
That's the reason I didn't go for the flyback transformer and because there would only be low voltage up to the gun.
If you think a fly back would be better then you are the master and I am the student.
The unit that's broken is sealed so dead.
The cascade in the picture is the new one.
I have to thank you for all your time and effort you've put into this. It's really appreciated.
Shall source the link and TRY and put it up now.
I thought you were here in the colonies:)

Now I'm confused. what in you machine is broken? You have a new gun, so is the control box broken too? If not why not just wire the new gun to the old controller?

With the cascade type gun, you only have low voltage from the control box to the gun, the cascade in the gun makes the high voltage(HV). The flyback is different, the HV is made in the controller and goes to the gun with a wire similar to a spark plug wire. That is how the professional coater machines work.

The link you gave is one using a flyback instead of a cascade to make the HV. To again just a quick look it should work, you would just wire the output they show as V1 to the cascade instead of the flyback transformer. I printed out the link to read it better, but think that is what they did.
 

Thread Starter

Roger60

Joined Feb 29, 2020
34
Thanks Gents.
Call my units (1 and 2.)
Unit 1 is my original ( broken )
Unit 2 is being made.
Unit 1 has the ( broken controller) 240ac to a 30v trigger relay feeding the ( HV sealed unit ) which is broken.
A few weeks previous I purchased the new gun which, I thought was better. I then purchased the cascade for the gun with the intention of using it with the controller ( number 1 ). The controller is different and broken now so I thought I would try and make a controller for ( gun 2 ) with 12v cascade.
I hope this helps.
As I already have components new, I thought electronic was better. If I get a fly back transformer the new gun ( 2 ) could still be
used without the cascade.
So sorry to confuse people and hope I haven't offended You or MrBill.
Kindest regards
 

MisterBill2

Joined Jan 23, 2018
9,882
Thanks Gents.
Call my units (1 and 2.)
Unit 1 is my original ( broken )
Unit 2 is being made.
Unit 1 has the ( broken controller) 240ac to a 30v trigger relay feeding the ( HV sealed unit ) which is broken.
A few weeks previous I purchased the new gun which, I thought was better. I then purchased the cascade for the gun with the intention of using it with the controller ( number 1 ). The controller is different and broken now so I thought I would try and make a controller for ( gun 2 ) with 12v cascade.
I hope this helps.
As I already have components new, I thought electronic was better. If I get a fly back transformer the new gun ( 2 ) could still be
used without the cascade.
So sorry to confuse people and hope I haven't offended You or MrBill.
Kindest regards
I am certainly NOT offended! A bit confused,yes, but I see nothing to be offended by. The term "cascade"seems like a reference to a voltage multiplier, a more common description of an arrangement using diodes and capacitors to multiply an input voltage. So it seems that the original spray gun has an external power supply, and a relay described as a trigger relay. That is confusing since it is unclear to me if that relay simply provides an on/off function, or if it is serving to provide the very rapid pulsing to somehow produce a high voltage from the "HV sealed unit" which you state is broken. I guess that is where the question about relay switching speed versus transistor switching speed came from.
I am guessing that the second gun is quite different in that it uses a flyback transformer and rectifier arrangement to produce the high voltage, and that a relay controlled by a trigger switch on the new gun will switch on both the air valve and the flyback type high voltage power supply.

Please let us know if these guesses are correct. It might be that the only failed part on the first gun system is actually that relay, if it was supposed to deliver the fast switching of the 30 volts DC. That is a guess on my part.
 

shortbus

Joined Sep 30, 2009
8,971
So sorry to confuse people and hope I haven't offended You or MrBill
Like mrbill, I'm in no way offended but am now even more confused.:) Actually you have been much better than some that come here to find help. The ones that go on for many pages of posts before finally telling what they actually want to know.

That said, maybe show a picture of both units, so we can get a better idea of what your trying to do would be more helpful. More helpful than a verbal description.
 

Thread Starter

Roger60

Joined Feb 29, 2020
34
Hi Both, I shall try to confuse you more
The first picture shows the ( broken) I believe you call them HARBOUR freight.
The black box is the sealed unit which is broken.
The circuit board is ok apart from transformer missing (I took it out).
The blue relay is working fine.P_20200305_162923.jpg

PLEASE NOTE: THIS IS THE BROKEN UNIT ( 1 )
 
Last edited:

Thread Starter

Roger60

Joined Feb 29, 2020
34
This is a ( similar ) unit sold from China with the same gun used with above unit.Screenshot_20200303-015108.jpg

PLEASE NOTE: THIS IS THE SAME AS THE BROKEN UNIT (1)
 
Last edited:

Thread Starter

Roger60

Joined Feb 29, 2020
34
I purchased this ( gun ) a few weeks ago hoping to make a new controller for it.P_20200304_164002.jpg

I then purchased the 12v voltage multiplier (cascade unit ) the white thing sticking out the back of the gun.
The gun is more adjustable as it comes with different tips.
This gun just needs an ( electronic control unit for the 12v cascade, voltage multiplier) OR ( a control unit with a Flyback transformer ) to supply this gun.
Thank you for sticking with me.

PLEASE NOTE: THIS IS GUN ( 2)
 
Last edited:

MisterBill2

Joined Jan 23, 2018
9,882
I purchased this ( gun ) a few weeks ago hoping to make a new controller for it.View attachment 200702

I then purchased the 12v voltage multiplier (cascade unit ) the white thing sticking out the back of the gun.
The gun is more adjustable as it comes with different tips.
This gun just needs an ( electronic control unit for the 12v cascade, voltage multiplier) OR ( a control unit with a Flyback transformer ) to supply this gun.
Thank you for sticking with me.
A 12 volt DC supply to power that high voltage supply would be simple to create, if you chose not to purchase one. A device that is supplied by 12 volts and delivers quite a few thousands of volts is not a voltage multiplier, it is a high voltage power supply. t probably includes a power oscillator, a step-up transformer, and a diode string voltage multiplier.
The reflections from that black block in the first photo make it very difficult to read the writing on the case. If that block is not solidly encapsulated it may be that it can be broken open and possibly repaired.
Do you have any information about the required power, (voltage and current) of any of the devices? And any statements about the actual high voltage and current?
 

Thread Starter

Roger60

Joined Feb 29, 2020
34
The black box is supplied by 240vac then reduced to about 36v then through rectifier to the relay which oscillates dc to the black box which is resin sealed.
 

Thread Starter

Roger60

Joined Feb 29, 2020
34
I have kept this separate as I am now referring to the gun with the cascade sticking out the back.
The green circuit board is the controller circuitry for it.
PLEASE NOTE: REFERING TO GUN ( 2 )
 
Last edited:

MisterBill2

Joined Jan 23, 2018
9,882
The black box is supplied by 240vac then reduced to about 36v then through rectifier to the relay which oscillates dc to the black box which is resin sealed.
"the relay which oscillates "??? Do you mean that the relay sounded like a buzzer? I wold have guessed that the black box included an oscillator circuit.
My guess is that the 36 volts DC is fed through the relay to an oscillator and transformer in the black box. Chattering relays have a terribly short lifetime.
 

MisterBill2

Joined Jan 23, 2018
9,882
I have kept this separate as I am now referring to the gun with the cascade sticking out the back.
The green circuit board is the controller circuitry for it.
That new gun, with the internal high voltage supply device sticking out the back, appears like it will need to be supplied with 12 volts DC, not 36 volts. If you choose to use the control box from the failed system you will need to have a 12 volt supply and a 12 volt relay to switch it on and off. That should be an easy project. If you can use the same white high voltage supply with the older gun and that box then the older unit will also need the same supply. 230 volts into the supply, 12 volts DC out. But be very careful about the polarity, it matters a lot.
 

Thread Starter

Roger60

Joined Feb 29, 2020
34
Gun 2 has the cascade which is supplied by 12v.
As for the blue relay you are right. There must be as you say, it has an internal oscillator.
I would like to use gun 2 but as it only requires a 12v supply the output is not going to be very high.
In order for the system to function well it would need 100kV but that sort of figure is professional equipment.
If I can achieve 50kV then that would make me a happy man. The ideal would be variable voltage and current.
The frequency needs to be around 15 - 30KHz.
If I can make something to build on that would be brilliant.
Regards Roger.
 
Last edited:

MisterBill2

Joined Jan 23, 2018
9,882
Gun 2 has the cascade which is supplied by 12v.
As for the blue relay you are right. There must be as you say, it has an internal oscillator.
I would like to use gun 2 but as it only requires a 12v supply the output is not going to be very high.
In order for the system to function well it would need 100kV but that sort of figure is professional equipment.
If I can achieve 50kV then that would make me a happy man. The ideal would be variable voltage and current.
The frequency needs to be around 15 - 30KHz.
If I can make something to build on that would be brilliant.
Regards Roger.
I have some good news, which is that the required input voltage does not predict the output voltage on an oscillator type of power supply. The output is determined by the winding turns ratio and the internal regulator setting. Often, though, the output may be ratiometric with the input, but only up to some point. Higher than that and parts fail. So before you presume the worst, give it a try. I predict that there will be enough high voltage.
 

shortbus

Joined Sep 30, 2009
8,971
Roger, did that cascade come with that #2 gun? How do you know it needs 12V?

Does the trigger on gun #2 control the air or is it just an electrical switch?

Instead of posting a screen shot of things like the one in post #32 or anyother thing you have for this project, please give a link, that way it is simpler to give information that will help you, faster. We can that way see for our selves what is needed. I really want you to get something working.
 

shortbus

Joined Sep 30, 2009
8,971
I would like to use gun 2 but as it only requires a 12v supply the output is not going to be very high.
In order for the system to function well it would need 100kV but that sort of figure is professional equipment.
If I can achieve 50kV then that would make me a happy man. The ideal would be variable voltage and current.
If you read more about this, powder coating, you will see that different kinds of parts take different voltages. Things with holes or hollows in them will only need ~25KV, and flat surfaces can take ~50KV. The reason for the two voltages is that after a certain point voltage wise, the holes and hollows won't get coated the ions on the parts keep the powder from getting into them.

The current is something that will take care of it's self when using a cascade or Cockcroft-Walton generator.
 
Top