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Alex:
To return tekfan's favour for doing a review of the Bruel & Kjaer 2305 recorder and continue his contribution, here is a list of products I would happily dissect:

Fluke 123 scopemeter
Fluke 289 DMM (upon enough demand)
TTi Ex354 Dual Power Supply
TTi TG550 function generator
Ersa I -CON 2 (with serial port) soldering station
Peak Atlas ESR60 ESR meter and Atlas DCA55 semiconductor analyser
Tektronix 2225 dual channel analog oscilloscope

Ernie Milko:
Definitely a yes please for the Peak kit.
From what I've seen of it, it looks a bit mickey-mouse.

Alex:
Teardown of Peak Atlas ESR60 ESR meter and Atlas DCA55 semiconductor analyser

Hard case the instruments come in. This is purchased separately.



The case has a foam insert with cutouts for two instruments, their leads and a spare 12V battery which is a great idea. Unfortunately no provision was made for the third instrument Peak makes in this category (the Peak SCR analyser) although there is space. A small pocket could be there to hold the user manuals. Overall a robust storage case.



The ESR60 measuring a 1uF MKT and a 100nF MLC capacitors.



Detail of the probes. They are gold-plated crocodile clips. There is no grommet on the case but the cables and entry point are very robust. Standard pozidriv screws, no metal thread inserts. However, the long screw length combined with coarse threads make a very robust and long-lasting mechanical joint between the enclosure pieces.



Top cover off. Notice the programming header on the left (Microchip ICSP) and the 12V battery in-PCB mounting on the right. 3 plastic feet press the battery towards the back. A standard Hitachi HD44780 compatible 2x16 LCD is used in I believe 4-wire parallel mode. The LCD is supported only by the connector, no double sided foam was used on its back.



View of the back of the PCB. On the left are the power supply electronics around a NI LDO. In the middle is the power mosfet in SOIC8 and power resistors. This is used to discharge capacitors before measurements. At the bottom a huge bi-directional zener diode connected directly across the capacitor measurement leads for over voltage protection. Notice that two wires were used for each croc clip for reduced resistance and increased reliability. On the top a PIC16F clocked externally with at 4MHz. Top right are two quad TI TLV2624 op-amps. Bottom right two Maxim MAX4614 quad analogue switches and two NAiS signal relays for routing the capacitor to the measurement and discharge circuit. These realys are very loud for their size.



Detail of the above




Over to the Atlas DCA55 semiconductor analyser. Here it is analysing an MPSA92 transistor. One complain is about the quality of the test clips. Their low cost is clear, but the real issue is with the hook of the tip which, when testing large transistors, can be bent under the force of the spring in the test clip. As a customer I would be happy to pay the extra £2-3 for a higher quality hook clips - even for infrequent use. They can however be desoldered and replaced with higher quality ones.



Top cover off, you can immediately realise Peak's business model. The units are nearly identical. Interestingly this PCB carries the name of Jez Siddons who (according to a forum) designed the ESR60. His name does not appear on the other board though.



On the back a PIC16F can be seen again, it is exactly the same as the ESR60, but lacks the external crystal oscillator as this meter doesnt require such high timing precision. On the right of the MCU are two 8-channel analogue multiplexers of the 74HC family. On the left is an LM324 quad op-amp. The input connections lack any form of protection.



And finally here are the two boards side by side.

Kiriakos-GR:
Nice Work Alex ...

Great pictures and text .

I just wish, that the time that you had use so to make the tear-down,
to no be stolen from the hours of your studies .  :)

Regards.

 

Alex:
Compares fairly with custom DMM stands...or watching the wedding.

That's our breed, super efficient to find time for the things we truly find pleasure in doing.

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