Main > Monitor/Video Forum
Arcade monitor isolation transformer.
abispac:
thank yall for the help...
lilshawn:
--- Quote ---so im trying to use an old 19 crt monitor i had laying around.
--- End quote ---
this doesn't help. it may need an isolation transformer...it may not.... it's going to depend on the monitor if it does or not.
i am going to suspect that if you plugged it in directly and it DID work (if even for a couple minutes even) and didn't IMMEDIATLY fry on you... it doesn't need isolation... and the reason for it's failure is unrelated.
monitors that need isolation basically instantly die the millisecond you plug them directly to mains.
abispac:
--- Quote from: lilshawn on March 20, 2020, 01:09:47 pm ---
--- Quote ---so im trying to use an old 19 crt monitor i had laying around.
--- End quote ---
this doesn't help. it may need an isolation transformer...it may not.... it's going to depend on the monitor if it does or not.
i am going to suspect that if you plugged it in directly and it DID work (if even for a couple minutes even) and didn't IMMEDIATLY fry on you... it doesn't need isolation... and the reason for it's failure is unrelated.
monitors that need isolation basically instantly die the millisecond you plug them directly to mains.
--- End quote ---
I know some times you got to play by the rules, but to be honest, 2 to 3 years ago, arcade cabinets with classic xbox were very popular around here, and i always saw monitors connected directly to the outlets with no problems, in fact i never saw one connected to an iso. so my though was that maybe this is the first one to require one. Im try to use it as is and post result to see if it burns back again.
lilshawn:
older monitors (80's early 90's) used a voltage regulator to create the main B+ voltage (usualy 130 to 160V DC) this voltage is not referenced to ground. the chassis has it's own "ground" a "chassis ground". problem is... your power coming out of your outlet is neutral referenced and grounded.
see, the neutral leg of the AC is tied to ground. problem is, if you plug this type of monitor directly into the wall, you effectively short all your B+ into ground. kerpow, you kill the regulator and likely the output stage diode(s).
newer monitors (like the last 30 years or so) rethought the design and instead use switchmode power supplies which use high frequency pulsed DC into a transformer to make power... this transformer takes the place of an isolation transformer since there is now a physical separation between the AC power going in and the DC coming out.
for the sake of ease, some really cheap china made monitors made near the end of the CRT era did require isolation...this was because there was a bit of a resurgence in the regulated power supply style of power (likely due to a handful of cheap parts being readily available at the time) they could throw a fistfull of transistors, FET's and diodes and make an inexpensive regulated supply.
abispac:
--- Quote from: lilshawn on March 21, 2020, 12:25:57 am ---older monitors (80's early 90's) used a voltage regulator to create the main B+ voltage (usualy 130 to 160V DC) this voltage is not referenced to ground. the chassis has it's own "ground" a "chassis ground". problem is... your power coming out of your outlet is neutral referenced and grounded.
see, the neutral leg of the AC is tied to ground. problem is, if you plug this type of monitor directly into the wall, you effectively short all your B+ into ground. kerpow, you kill the regulator and likely the output stage diode(s).
newer monitors (like the last 30 years or so) rethought the design and instead use switchmode power supplies which use high frequency pulsed DC into a transformer to make power... this transformer takes the place of an isolation transformer since there is now a physical separation between the AC power going in and the DC coming out.
for the sake of ease, some really cheap china made monitors made near the end of the CRT era did require isolation...this was because there was a bit of a resurgence in the regulated power supply style of power (likely due to a handful of cheap parts being readily available at the time) they could throw a fistfull of transistors, FET's and diodes and make an inexpensive regulated supply.
--- End quote ---
:laugh2: :laugh2: :laugh2: im so dumb :laugh2: :laugh2: :laugh2: so should i tried it without an iso or no?