Build a Nice Load box. Metering, open load 2,4,8 and 16 Ohm all switcheds

GeorgeP

Journeyman
Joined
Mar 22, 2023
Messages
102
#1
Hi to all,
I just finished my universal testing load box for monster amplifiers:
1. Uses 300-Watt 8 Ohm Resistors, fan cooled
2. Has all the switching for:
A. Open Load
B. 2, 4, 8 and 16 OHMS, Power Dissipations based on Impedance chosen...up to 1200 Watts
C. Dual LCD metering for each channel, RMS Volts calibrated.
D. Scope output on BNCs with X10 Voltage divider for each channel
E, Dual Fans for Cooling things down.
All switches use brass screws, made tight and then soldered. All wiring for load carrying is #10 Heavy insulated, and properly crimped with a special tool for those lugs.
Schematic is a .pdf from Orcad and has part numbers for most Items. top full view.jpg rear pic.jpg Full bottom pic.jpg front open view.jpg Left side LCDs.jpg front open view.jpg
Schematic and Pictures below:
 

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GeorgeP

Journeyman
Joined
Mar 22, 2023
Messages
102
#3
Hi to all,
I just finished my universal testing load box for monster amplifiers:
1. Uses 300-Watt 8 Ohm Resistors, fan cooled
2. Has all the switching for:
A. Open Load
B. 2, 4, 8 and 16 OHMS, Power Dissipations based on Impedance chosen...up to 1200 Watts
C. Dual LCD metering for each channel, RMS Volts calibrated.
D. Scope output on BNCs with X10 Voltage divider for each channel
E, Dual Fans for Cooling things down.
All switches use brass screws, made tight and then soldered. All wiring for load carrying is #10 Heavy insulated, and properly crimped with a special tool for those lugs.
Schematic is a .pdf from Orcad and has part numbers for most Items. View attachment 76197 View attachment 76198 View attachment 76199 View attachment 76202 View attachment 76200 View attachment 76202
Schematic and Pictures below:
 
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