Pro Audio Design Forum

2SB737 has become unobtainium.
No hit on octopart.
High prices on unreliable sources, risk of fakes.

With low cost in mind. ZTX1053 or ZTD1053 paralleling can give a lowest noise and better Vbe Hfe matching.

My thought was the dual SMT could have a metal slug glued onto it to equalize the temperatures (and add thermal mass) as well as a PCB pour under it. What do you mean by a PCB pour under it ? Some thermal pad. I was struck by the thermal resistances mentioned in the ZTD1053 datasheet. The Rth from ...

Great. From the ZTD1053TA datasheet. There is no information about transistor matching. Foot notes at thermal characteristics, indicate the two transistors are on separate dies. It is not clear wether we are better with a dual ZTD1053 rather than with two singles ZTX1053 we can match. The case is pl...

I had a look at the specs. Their second float bit is non sense to me, why not a third one in case the second one fails...

Hysteresis is a worthwhile improvement. Here two floats would make sense.
As said, one to cut in the other to cut off.

The new bigger sump pump makes quick work of accumulated water... What used to take hours with the old 1/4 HP pump pushing water through 3/4" garden hose, now takes minutes with 1/2 HP and 1.25 discharge hose.... Good move. Twice the power, 2.8 times more hose section. Plus a better efficiency...

Who knows in this world of near no cost micro processing power and software. Their specifications are vague if any. Some mentions "power factor", saying nothing more than these two words about it. Power factor makes sense for motors but doesn't make sense for most power electronics used no...

True watt measurement might make a difference especially to see about a motor idling versus running under load.

This raises the question:
Is it measuring W or VA ?
Cheapos may even be measuring A scaled by a standard V.

I suggest you look at the phase. Phase of I relative to V. I presume the motor is an asynchronous motor, this is usually what is used for water pumps. I remember the torque directly relates to speed slipping. I do not remember wether torque relates to phase. Who knows, may be the phase gives some in...

Prices and qualities are becoming more and more unpredictable. Cost and quality of shipment, payment refund reliability too. Now days, price has little to do with manufacturing cost, the price is more, what the buyer can be induced to pay. In Europe and Asia, they have reactivated railroad transport...