power supply for crt

Thread Starter

uv147

Joined Dec 24, 2015
18
hi
i am quite new to the topic and this is my first project
i want to buy a crt from a tektronix oscilloscope, and it's service manual says the the cathode needs a -1900V supply and the anode uses another 14kV, and i also know there is a heater but nothing is stated about it in the manual,
i need the crt to operate without the rest of the oscilloscope and, but i only need the electron beam to be formed, i don't need the deflection plated as i intend to deflect the beam using an external magnetic field.
does anybody know how can i generate the required voltage?
thank you very much
 

MaxHeadRoom

Joined Jul 18, 2013
20,866
I would have thought it would be easier to look for 'scope with inputs to the X & Y plates as some older ones do for for displaying Lisajous figures etc..
Another alternative is find an old small monochrome monitor and take the deflection coils off the neck of the CRT.
Max.
 

Thread Starter

uv147

Joined Dec 24, 2015
18
I would have thought it would be easier to look for 'scope with inputs to the X & Y plates as some older ones do for for displaying Lisajous figures etc..
Another alternative is find an old small monochrome monitor and take the deflection coils off the neck of the CRT.
Max.
The point of this project is to use magnetic field to deflect the beam,
i tried looking for monochrome monitor but they cost too much
 

withoutego

Joined Dec 22, 2015
26
Find one of those old portable TVs where everything but the CRT is solid state. The electronics bin at the dump, attics, barns. It gives you the HV and magnetic deflection coils. You can run your own current source into the pair of coils .... or have fun with permanent magnets. IAW, Get something where all the work of putting a spot electron beam on the phosphor is already taken care of. But those old sets are getting scarce.
 

spinnaker

Joined Oct 29, 2009
7,835
This is way, way beyond a first project. Believe me when I tell you that you want to be awfully careful around HV supplies for CRTs. I used to repair televisions back in high school. I learned that lesson one time and it was all that I needed for it to sink in.
 

crutschow

Joined Mar 14, 2008
25,103
This is way, way beyond a first project. Believe me when I tell you that you want to be awfully careful around HV supplies for CRTs. I used to repair televisions back in high school. I learned that lesson one time and it was all that I needed for it to sink in.
Yes, getting zapped by a few thousand volts does tend to stay in one's memory. ;)
 

MaxHeadRoom

Joined Jul 18, 2013
20,866
Although being having been around many industrial potentially dangerous procedures and the results of 'Accidents' , it my experience that it is usually the trainee and neophyte that practices extra caution, the long time experienced seem to be come jaded and drop their guard, and these are usually the ones that become harmed.
Max.
 

withoutego

Joined Dec 22, 2015
26
Yes, treat HV like you would a cobra or table saw, keep your
attention focused. And I agree, an old O'scope with direct X-Y
input would do the job without modification and keep the HV
isolated.

Everyone wants to be another Tesla, HV is so exciting.
 

#12

Joined Nov 30, 2010
18,210
Just checking...do you realize that a, "yoke" is a magnetic field generator?
The yoke is an old word for the coils mounted on the neck of the CRT.
 

ISB123

Joined May 21, 2014
1,236
This is way, way beyond a first project. Believe me when I tell you that you want to be awfully careful around HV supplies for CRTs. I used to repair televisions back in high school. I learned that lesson one time and it was all that I needed for it to sink in.
Now you know how PROM feels.:D
 

DickCappels

Joined Aug 21, 2008
6,451
High Voltage Power Supplies
If you have some money to spend, you can buy laboratory power supplies from those who manufacture them.

Spellman Hight Voltage Electronics Corporation comes to mind:
http://www.spellmanhv.com/

TV Sets/Computer Monitors
uv147 might not recognize the opportunity
represented by an old monochrome CRT television or computer monitor chassis. One can remove the deflection coils (yoke) from the CRT and expose the CRT to the magnetic fields you are interested in. In most monitors the deflection yoke must remain in the circuit or appropriate coils substituted because they are necessary for the generation of high voltage and in some cases they affect circuits that wold blank the CRT in the event of circuit failure.

Old Ball Brothers/Miratel

Stay away from color tubes -too many beams to worry about plus the internal magnetic shields might interfere with your experiments/observations.

@#12 The term "yoke" is appropriate since it goes around the CRT's "neck".
 

Thread Starter

uv147

Joined Dec 24, 2015
18
High Voltage Power Supplies
If you have some money to spend, you can buy laboratory power supplies from those who manufacture them.

Spellman Hight Voltage Electronics Corporation comes to mind:
http://www.spellmanhv.com/

TV Sets/Computer Monitors
uv147 might not recognize the opportunity
represented by an old monochrome CRT television or computer monitor chassis. One can remove the deflection coils (yoke) from the CRT and expose the CRT to the magnetic fields you are interested in. In most monitors the deflection yoke must remain in the circuit or appropriate coils substituted because they are necessary for the generation of high voltage and in some cases they affect circuits that wold blank the CRT in the event of circuit failure.

Old Ball Brothers/Miratel

Stay away from color tubes -too many beams to worry about plus the internal magnetic shields might interfere with your experiments/observations.

@#12 The term "yoke" is appropriate since it goes around the CRT's "neck".

so i can just buy one of the those portable monochrome tvs on ebay, open it up, remove the deflection coils, and use the rest of the tv for my project?
or are there only specific models in which the coils are removable?
 
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