Search found 171 matches

by terkio
Thu Apr 02, 2020 6:45 am
Forum: The Peabody Lounge
Topic: home improvement turns into science fair projects?
Replies: 182
Views: 9465

Re: home improvement turns into science fair projects?

Pecan nut harvest.
Have you seen good and bad years, trouble from long drought periods.
Any tips about Pecan trees care.
by terkio
Wed Apr 01, 2020 6:08 pm
Forum: The Peabody Lounge
Topic: home improvement turns into science fair projects?
Replies: 182
Views: 9465

Re: home improvement turns into science fair projects?

I missed something.
What is the purpose of your tree sprayer ?
by terkio
Tue Mar 17, 2020 10:07 am
Forum: Pro Audio Design
Topic: Low Noise Transistors: Comparing the ZTX1053A and ZDT1053 (Dual) vs. the ZTX689B and ZTX851
Replies: 16
Views: 422

Re: Low Noise Transistors: Comparing the ZTX1053A and ZDT1053 (Dual) vs. the ZTX689B and ZTX851

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.
by terkio
Wed Mar 11, 2020 4:59 am
Forum: Pro Audio Design
Topic: Low Noise Transistors: Comparing the ZTX1053A and ZDT1053 (Dual) vs. the ZTX689B and ZTX851
Replies: 16
Views: 422

Re: Low Noise Transistors: Comparing the ZTX1053A and ZDT1053 (Dual) vs. the ZTX689B and ZTX851

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 ...
by terkio
Tue Mar 10, 2020 4:34 pm
Forum: Pro Audio Design
Topic: Low Noise Transistors: Comparing the ZTX1053A and ZDT1053 (Dual) vs. the ZTX689B and ZTX851
Replies: 16
Views: 422

Re: Low Noise Transistors: The ZTX1053A and ZDT1053A (Dual) vs. the ZTX689B and ZTX851

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...
by terkio
Sat Mar 07, 2020 7:23 pm
Forum: The Peabody Lounge
Topic: home improvement turns into science fair projects?
Replies: 182
Views: 9465

Re: home improvement turns into science fair projects?

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.
by terkio
Fri Mar 06, 2020 1:41 pm
Forum: The Peabody Lounge
Topic: home improvement turns into science fair projects?
Replies: 182
Views: 9465

Re: home improvement turns into science fair projects?

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, I p...
by terkio
Fri Mar 06, 2020 11:10 am
Forum: The Peabody Lounge
Topic: home improvement turns into science fair projects?
Replies: 182
Views: 9465

Re: home improvement turns into science fair projects?

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 nowadays, so...
by terkio
Thu Mar 05, 2020 11:02 pm
Forum: The Peabody Lounge
Topic: home improvement turns into science fair projects?
Replies: 182
Views: 9465

Re: home improvement turns into science fair projects?

True watt measurement might make a difference especially to see about a motor idling versus running under load.
by terkio
Thu Mar 05, 2020 3:10 pm
Forum: The Peabody Lounge
Topic: home improvement turns into science fair projects?
Replies: 182
Views: 9465

Re: home improvement turns into science fair projects?

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