28-11-2016, 06:57 AM
Thanks Lawrence, i'll look those links etc up .
To be honest I don't really care about the small inductance present on my dummy load at the moment, but as I,ve got more interested in testing amplifiers and read up on the subject, quite a lot of bumf has mentioned non inductive R's. I was interested in the method as it looked to be a cheap way to get non-inductive loads, and thought I'd run it past the boffins. The Arcol NHS** R's Nick mentioned not being cheap at £50 for one 100w 8 ohm resistor, the HS versions look cheaper though.
Nice dummy load Mark, why the earth? Safety or something else? Wouldn't have thought of using a Zobel network.Those are huge HS's your using. The first power resistors I bought years ago for use as dummy loads were cheap no datasheet jobbies. Last week I bought some Vishay R's which did. For one 50w R it stipulated a HS 5" x 7" x 2" which surprised me, so your titanic HS's no longer seem big. The temp figure is academic as all my HS's are second hand retrieved.
Don't know about lft/rght handed R's Sam, but you could definately sell a few audio dummy loads, maybe with a combined watt meter and two VU meters. Anything with VU, MM meters on is a winner. : )
So it looks like I'm going to need bigger HS's than I'm using. I have some big HS's out of a welder with fans on that look the job, but that means it's going to be big and take up room on my tiny workbench. I found a thermal switch in the junkbox that may be good to include to switch off am amp in case of temperature overload, it switches off at 170 deg C. I've been relying on touch.
Andy.
To be honest I don't really care about the small inductance present on my dummy load at the moment, but as I,ve got more interested in testing amplifiers and read up on the subject, quite a lot of bumf has mentioned non inductive R's. I was interested in the method as it looked to be a cheap way to get non-inductive loads, and thought I'd run it past the boffins. The Arcol NHS** R's Nick mentioned not being cheap at £50 for one 100w 8 ohm resistor, the HS versions look cheaper though.
Nice dummy load Mark, why the earth? Safety or something else? Wouldn't have thought of using a Zobel network.Those are huge HS's your using. The first power resistors I bought years ago for use as dummy loads were cheap no datasheet jobbies. Last week I bought some Vishay R's which did. For one 50w R it stipulated a HS 5" x 7" x 2" which surprised me, so your titanic HS's no longer seem big. The temp figure is academic as all my HS's are second hand retrieved.
Don't know about lft/rght handed R's Sam, but you could definately sell a few audio dummy loads, maybe with a combined watt meter and two VU meters. Anything with VU, MM meters on is a winner. : )
So it looks like I'm going to need bigger HS's than I'm using. I have some big HS's out of a welder with fans on that look the job, but that means it's going to be big and take up room on my tiny workbench. I found a thermal switch in the junkbox that may be good to include to switch off am amp in case of temperature overload, it switches off at 170 deg C. I've been relying on touch.
Andy.
