The voltage drop over the SSHV2 reg only affects the on-board sink. If it ain't overheating, no worries.
What is the range of voltage at the input to the regulator for the full range of mains electricity supply voltages?
10V in-out drop is good for the CCS and 20V is recommended so to ensure the 10V bottom level for somewhat varying mains during the day or from place to place average. Anymore than 20V is no problem as long as its not producing much heat along the CCS setting in mA.
SSHV1
Salas,
The voltage on my SSHV1 is drifting lately. The supply voltage is 217v. It starts at about 100v at the output then slowing drifts the way up to around 145v ( this is my desire voltage for the 26 B+ ) then drifting up and down. I have tried changing the 350, 840 and even all 4 12v zeners with no avail. Will it be the problem on the 9610 / or the 170 ??
Albert
Salas,
The voltage on my SSHV1 is drifting lately. The supply voltage is 217v. It starts at about 100v at the output then slowing drifts the way up to around 145v ( this is my desire voltage for the 26 B+ ) then drifting up and down. I have tried changing the 350, 840 and even all 4 12v zeners with no avail. Will it be the problem on the 9610 / or the 170 ??
Albert
Was MJE350 getting particularly hot for long periods before the excess drift appeared recently? Does it have some sort of sinking?
Is the 170 in hot environment? Provide it with some heat relief. A little foil or special TO-92 sink. If you will blow over the 170 while watching Vout you will know.
Is the 170 in hot environment? Provide it with some heat relief. A little foil or special TO-92 sink. If you will blow over the 170 while watching Vout you will know.
My mistake not checking the temperature on the 350, but now they're all new. I didn't put any sink onto them, I'll try doing this if it's necessary. No sink for 170 either.
The k170 has just 0.6V across it. It dissipates ~4mW. It never gets warm. It does not need a sink.
Not for that. To increase its thermal mass and keep it steadier to ambient. If its drifting so much due to K170 and ambient temp reasons in that build, of course.
If the temperature inside the case varies, then adding a sink to the jFET will drag the jFET Tc & Tj along with the varying Ta. It will make tempco worse not better.
However, the temperature inside the case should be reasonably stable. This will allow the jFET to hold it's own temperature ~ 1Cdegree above Ta.
However, the temperature inside the case should be reasonably stable. This will allow the jFET to hold it's own temperature ~ 1Cdegree above Ta.
Don't know, if the temp rise is the case maybe a BF245A lowest IDSS possible from a bunch or 2SK117GR could be steadier. But it has to be checked that the JFET is the one so much affected in that build.
Since I have the 840 & 350 replaced, does it mean it's a good idea to replace the 170 so to check ?