I saw a request for circuit diagram in Facebook electronics group: Hello feds. Required surge protector circuit. Working on 220v. 50hz 10amps load.
I first offered this reverse engineering of one commercial mains surge protector “Ahlstrom 23 368″.
The manufacturee component codes of the exact components used.
S20K250 is a varistor for 250V AC / 320V DC (390V varistor operating voltage) 140J 8kA
UZ470B32 is a gas discharge tube surge arrestor with voltage rating of 470V
Unfortunately it seemed that the UZ470B32 TUBE was no longer available.
Then I mentioned that some commercial surge protectors and built in protection inside some power supplies have been built with only VDR between live and neutral (and some cases between neutral and ground, and sometimes even live and ground).
I decided to make a tear-down and reverse-engineering of another commercially sold surge protector (no brand name on case). It uses three 14D471 varistors and indicator lamp (glimm lamp with 120 kohms current limiting resistor). The 14D471 varistors are 14 mm diameter 470V DC rated (300V AC). One is between live and neutral. The other two are from live to ground and neutral to ground.
8 Comments
Tomi Engdahl says:
https://www.epanorama.net/documents/surge/surgesuppres.html
Tomi Engdahl says:
https://www.edn.com/a-circuit-simplification-for-ac-power-supply-surge-protection-devices/
Tomi Engdahl says:
Lightning/Surge Protector Circuit Using Gas Discharge Tube (GDT)
https://www.circuitstoday.com/lightningsurge-protector-circuit-using-gas-discharge-tube-gdt
Tomi Engdahl says:
Y08UZ-470B New plug-in ceramic gas discharge tube UZ470B 470V lightning pipe U-9B 2R470.
https://www.yoycart.com/Product/521928929749/
Tomi Engdahl says:
Never Use a Surge Protector with a Step-Down Transformer
https://www.gson.org/stepdown/
Tomi Engdahl says:
SurgeX Surge Protection Demo
https://www.youtube.com/watch?v=dlByve0r7GE
See how SurgeX Advanced Series Mode surge protection technology safeguards electronic equipment.
Tomi Engdahl says:
How different surge protectors respond to a surge
https://m.youtube.com/watch?v=fqR4N9LH0Qs&feature=youtu.be
This short white-board demonstration shows how various surge protection technologies acts when a surge passes through a power line.
Zero Surge is a USA manufacturer of series mode failure-free surge protection products for computers, TVs, gaming consoles, audio equipment, copiers, security systems, CPAP and medical equipment, laboratories, Point of Sale systems, digital menu boards, teleconferencing equipment, CNC machinery, and countless other sensitive electronics. The product line consists of plug-in point of use products, 20 Amp branch circuit panel mount models, and OEM open chassis modules for inclusion in a manufacturer’s product design.
Spectrum WVR – Wide Voltage Range Technology-
Typical surge suppressors use fixed clamping level components such as Metal Oxide Varistors (MOVs) that do not even begin to function until their clamping level is exceeded, allowing damaging energy through until that, often too high, level is reached. Using a patented dynamic clamp surge inversion system, Zero Surge’s Spectrum WVR effectively senses and suppresses surges on your 120VAC power line even when the power is low at 85 Volts or high at 175 Volts and anywhere in between. This is especially beneficial when the voltage is variable and unpredictable, during brownout and blackout conditions, and when standby generators are in use.
Tomi Engdahl says:
What you need to know about SPDs
https://www.youtube.com/watch?v=S85iSQ3_kQo
After one of our last videos, we had a lot of people wanting to know more about SPDs and how they actually work. With a lot of people still opting to not use them on their installations.
So we dig into the three main questions:
1) What are Type 2 SPDs
2) How do they work
3) Do they need Overcurrent Protection?