NGMO1 0-15V 0-2.5A power supply teardown (Rohde & Schwarz)

[thmjpr]

NGMO1 multi-feature power supply (manual).

Basic specs:
- 0-15V at 2.5A
- Ripple + noise: <1mVrms
- Set resolution: 1mV, 1mA
- Read resolution: 1mV, 200uA/10uA/0.1uA (depending on range)
- Accuracy: 0.05 % +5 mV, +/-10mA
- 1A+ current sink


Front of the supply. Rotary encoder broken during shipment and will have to get a replacement (ECW0J-B24-AC0006).
Oddly someone had sharpied over the "Made in Germany" text in the bottom right.



Bottom of the unit contains the main processor, communications, and bulk capacitance. Caps are 85C rated but I can't see this board getting very warm.
Proper mains switch seen crossing the top. Minimal input filtering on the top left.



LEDs for various rails: 5V, +/-8V, 16V, 24V.
Opto's going off to output section on the other side.



- 16-bit micro (C167CR-LM)
- 8mbit flash (M29F800)
- 64K eeprom (at28hc64b)
- 2x1Mbit SRAM (HY628100B)



Top side of the PSU which contains either one or two mirrored supply boards + transformers.



- opamps: OP27, OP275, AD823, AD825, AD829
- 8-bit DAC (DAC08)
- 16-bit "low glitch" DAC (LTC1650)



- 12-bit dual DAC (LTC1446)
- 16-bit 195kSPS delta-sigma ADC (AD7722AS)
- 24-bit DSP (DSP56303PV100)
- 2x256K SRAM (IS61LV256)


A lot of the advanced functionality isn't usable via the front panel. A bit of a shame but expected as you would normally be using the PC analysis software (don't have it).

[robrenz]

Nice unit and pictures, what do these go for $ ?

[thmjpr]

Nice unit and pictures, what do these go for $ ?

Thank you. Retail is something like $4500, but they are not popular used.

Used prices for NGMO1 usually $3-400, NGMO2 $800.

I was able to purchase for much less from ebay user szmateton. He offered to sell more units if anyone else is interested.

[orion242]

Tearing into mine and figured I would add more pictures of the analog board...took off all the clothes.  Above 10v it goes unreg, so in we go...

[Qw3rtzuiop]

Ive been asked here how i done the display swap:
https://www.eevblog.com/forum/buysellwanted/(fs)(eu)rohde-schwarz-ngmo2-dual-channel-analyzerpower-supply/

The acrylic glas need to be changed to enhance the vfd contrast. I used 3mm grey tinted acrylic glas.

The vfd is a VFM202MDAR2-1. They are hd44780 compatible. You can get them on aliexpress and they are also in some cash registers.



Some jumpers need to be adjusted (parallel and M68 mode) and the connection cable needs to be soldered.
And while youre in there you should change the RIFA input caps. Why? Take a look here: https://www.eevblog.com/forum/chat/old-rifa-capacitors-and-a-disaster-story/
On the picture they are already changed.