Thursday, 29 October 2015

Teardown: LeCroy HVL100 Discriminator Hybrid IC

I found this hybrid IC in the analog front end of the Packard Liquid Scintillation Analyser i took apart some time ago.

As it was a hybrid i saved it to take a look at in the future and today i removed it's cover to see inside.

The IC has a standard 16 pin DIL pinout but is an oversized package. The package is ceramic with bonded gold plated pins. The top cover is also ceramic which is glued on top of the main body.

The HVL100 is manufactured by LeCroy, famous for their high-end oscilloscopes and other test equipment. It is a discriminator and is a combination of the LeCroy MVL407 4 Channel Comparator and the Motorola MC10198 Monostable Multivibrator. The HVL100 here dates from 1996 and the following text is from it's datasheet:

Click Image To Zoom

After some heating with a hot-air gun i was able to remove the top cover.

Inside is a ceramic substrate with the components bonded to it and usual gold bondwires connecting the silicon devices to the ceramic substrate.

There are a couple of ceramic capacitors and two main integrated circuits, i would hazard a guess the central one is the main LeCroy MVL407 comparator , you can easily see the 4 sections in the die. The smaller device to the right is the Motorola MC10198.

Notice also the blue covering on some of the signal traces, generally this seems to be when a bond wire passes over the trace so maybe this is to reduce capacitance between the two traces?

Click Image To Zoom

Click Image To Zoom

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Motorola MC10198. Note the copyright indication in the top right corner.

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LeCroy MVL407.

Tuesday, 20 October 2015

Tuesday, 13 October 2015

Teardown: Vintage Solartron LM1619 Volt Meter

In this teardown i take a look at a vintage Solartron LM1619 Digital Volt Meter. This is a UK made product which dates from around the early 1970s.

Full Teardown Video:

The LM1619 is a 1999 count volt meter only with DC ranges of 200mV, 2V, 20V, 200V and 1kV. AC ranges are 2V, 20V, 200V and 750V.

The unit weighs about 5Kg and is housed in an extruded aluminium chassis with vinyl covered steel covers. The front panel is a thin layer of beige Formica with cutouts attached to the chassis. Has integral tilting bale.

Connections are provided on the front with three banana jacks, HI, LO & CHASSIS.

The display consists of three Mullard ZM1080 Nixie Tubes. Decimal places, polarity indication and the 1000 count indication are provided by discrete neon lamps.

Inside there are three main areas:

DVM Board
which contains most of the electronics for the voltage measurement. This includes two vacuum tubes, a Mullard CV4003 valve and a Mullard 83A1 which is the voltage reference.

Display Board
This contains the components to drive the three nixie tubes and consists mainly of descrete transistors on a hinged PCB for easy maintenance.

Front End
Located within a shielded can this houses the voltage dividers and trimmers along with a Weston cell and what appears to be a battery connection. Although the battery was missing from my unit i am insure what the battery was for.

View from the top:

View from the bottom.

Sunday, 11 October 2015

Teardown: Avery Berkel D104 Post Office Scales

This is a short teardown of an Avery Berkel D104 Post Office Scales, as used in post offices throughout the UK.

The case is constructed of cast aluminium with a large aluminium bed, large 2x20 high contrast LCD display. The unit is intended to be bolted to a work surface.

Three data connections are located on the base.

Inside the unit the is the load cell, small mains transformer, and three significant PCBs, one has a selection of voltage regulators and analog circuitry for the load cell, the other two are what appears to be the digital processing board and then the display board.

Inside the unit, with the LCD & Display board removed from the front. The dataports are located on the far right. The digital controller board at the front, load cell in the centre and finally the analog board at the back. As shown in the picture below.

Below is the reverse of the display controller, the LCD module is mounted on the other side, with a IDC cable connecting on the right. It contains 64kbytes EPROM, Intel 8032AH Microcontroller, SRAM, Intel n825306 Serial Communications Controller and two MAX232 RS232 drivers. There is a small power supply section at the top left as this board runs from a separate transformer tap so is isolated from the other boards.

Below is the analog board, power supply regulation on the left with discrete diode bridge rectifier and linear regulators for the voltages needed for the analog side. The analog front end for the load cell is located in the area to the right where i have removed the shielding can.

The digital board below takes a IDC cable from the analog board, located at that connector is a custom ASIC and an 32kbyte EPROM. Also on this board is another Intel 8032AH microcontroller, MAX232 RS232 driver and four opto isolators. I would guess these are for the three external ports and the internal display board which uses RS232 between the two boards.

The load cell below is a 6kg rated device, no manufacturers name can be found on it, given Avery Berkel's size this could be of their own design.