Joules - surge protector question
I see surge protectors with differing values for joules.... but it doesn't say what is better ... is higher better than lower values ? thanks
Forum Discussion
Great Post IMHO SoundGuy
The ubiquitous "MOV" works well only on some transient voltage spikes, but not all.
Compare a MOV to a shock absorber or prize fighter. They can only take so much, then it's all over. They wear out. Having a bunch of MOV capacity means they will wear out more slowly.
Really fast acting high voltage short-duration transients is like placing a light middle-weight in the ring. Much faster and quicker than the heavyweight MOV. These faster transients can destroy integrated circuits just as certainly as slower longer duration voltage spikes.
Stick oscilloscope probes on a large transformer winding, load the transformer then shut it off and what you will see in the oscilloscope screen will make your hair stand out on end.
The same thing happens when motor windings are switched off under heavy load.
Design of a transient voltage suppression device is as much an artform as it is engineering skill. The art comes in when trying to make the thing work, live a long time and be affordable.
I loved it when I encountered a TVS diode rated 1,000 times higher capacity than my purchased Transient Voltage Suppressor diodes. Unfortunately the monster TVS was a thousand times the cost.
When it comes to purchasing a good voltage spike protector, beware of shady advertising that makes it sound like you are getting a big bowl of beef stew but you end up with a cup of hot water and a bouillon cube.
The ubiquitous "MOV" works well only on some transient voltage spikes, but not all.
Compare a MOV to a shock absorber or prize fighter. They can only take so much, then it's all over. They wear out. Having a bunch of MOV capacity means they will wear out more slowly.
Really fast acting high voltage short-duration transients is like placing a light middle-weight in the ring. Much faster and quicker than the heavyweight MOV. These faster transients can destroy integrated circuits just as certainly as slower longer duration voltage spikes.
Stick oscilloscope probes on a large transformer winding, load the transformer then shut it off and what you will see in the oscilloscope screen will make your hair stand out on end.
The same thing happens when motor windings are switched off under heavy load.
Design of a transient voltage suppression device is as much an artform as it is engineering skill. The art comes in when trying to make the thing work, live a long time and be affordable.
I loved it when I encountered a TVS diode rated 1,000 times higher capacity than my purchased Transient Voltage Suppressor diodes. Unfortunately the monster TVS was a thousand times the cost.
When it comes to purchasing a good voltage spike protector, beware of shady advertising that makes it sound like you are getting a big bowl of beef stew but you end up with a cup of hot water and a bouillon cube.
