Decent surplus finds, relay control board, Spartan based dumb terminal, big LCD - Page 1
Forum section: electronics / projects

author: Stonent
author_rank: Super Contributor
timestamp: December 27, 2014, 11:07:06 pm
content: I stopped by Tanner Electronics in Carrollton, Texas again because I felt the need to lighten my wallet again.Item 1: Large Hitachi Dot Matrix LCD $1.99I was immediately drawn to a shelf with some big monochrome graphical LCDs with about a dozen Hitachi chips on the back. The board was marked LM215 and I found a little information on it.Picture of the LCD (From google search)Apparently this doesn't have any real controller on it, the Hitachi chips are just for driving pixels, so in its original configuration which was apparently from some FedEx device there was a separate controller board. Without it, you need to manually clock and refresh each pixel on the board. It has 12 HD61100 chips and 2 HD61103 chips.Here's a datasheet:http://www.alltronics.com/mas_assets/acrobat/28L071.pdfItem 2: Pfannenberg Relay board $4.95 (Pics coming later today)I saw a decent sized circuit board with 2 40 pin DIP chips on it, several relays, some Alccor HS50 Aluminum mounted resistors for $4.95. I had to have it just to see what it was.I peeled the stickers off the 40 pin DIPs and they were both PIC 16F877A chips. There were numerous Vishay optocouplers and about 8 optocouplers covered in in a red coating on the top and bottom of the board.It had 4 24V drive , 250VAC rated relays, and a smaller one near the bottom of the board. Several traces were about 5mm wide that went to the spade connectors on the back and the big relays. The name Pfannenberg was silkscreened on the board with a part number but google searches on the part number got me nothing. Pfannenberg apparently makes industrial HVAC related hardware so I expect this relay board is for turning fans on or perhaps actuating motorized vents.The the parts on the board are far beyond the amount I paid for it. The PICs go for about $6.50 each on Digikey, the relays were I think around $10 or $20 each, the Alcor resistors are about $6.00 each. There was a TI precision OpAmp connected to a thermistor, 2 OnSemi OPAmps and 2 5C to 15C temperature controlled switches.It appears to take 120 or 240 volt input as the thick traces come out of some diodes in a bridge rectifier configuration, go all the way to the other side of the board where there's a blue octagon shaped inductor, a few capacitors, a 7805 and 7815. There's some high current IRF MOSFETs. In between the 2 regulators is a DC to DC converter (I'll get the part number later) that was listed in the datasheet as an unregulated DC/DC converter.On the back of the board is a DB15 connector and 8 LEDS and a single button. I presume it is to check the open/closed state of the relaysI was surprised by the lack of cut outs in the board near the high voltage traces, everything seems rather close.Hopefully I can dump the PICs to look inside and maybe reprogram them to use them to just actuate the relays in some kind of sequence. I will probably bypass all of the power supply area and just feed it +15 and +5 directly. No real plans to switch high voltage.Item 3: Pano thin client $9.95Depending on whether or not this was a Gen 1 or Gen 2, it has either a Spartan 3 or Spartan 6 FPGA on board. These were featured in Hackaday a few years ago as a possible cheap FPGA dev board. I haven't removed the heatsink yet but I think mine is a Gen 1 board because the Gen 2 board I saw online had a much bigger sized memory chip near the FPGA. There's a small 5 or 6 pin header near the FPGA. I haven't powered this on yet because I need to find a power supply that fits the barrel jack.Info on the thin clientshttp://hackaday.com/2013/01/11/ask-hackaday-we-might-have-some-fpgas-to-hack/So at just under $20 total spent. I'm pleased.The Pfannenberg relay board I'm most pleased with. It was worth it for just the PICs alone.(I'll post more pictures when I get home later today)

author: Stonent
author_rank: Super Contributor
timestamp: December 29, 2014, 06:55:38 am
content: Here is the relay board:More pictures here:http://imgur.com/a/r4tIM/embedI fed some power to the 7815 and the relays clicked and the LEDs on the back started flashing green. After about 15 seconds one went solid green and every 15 to 20 seconds the others would turn red in pairs until they all were red except the first one.The markings on the board indicate a mid 2004 build date.Here are the interesting parts:Code:Optocouplers:Vishay ILD615-312http://www.vishay.com/docs/83652/ild615.pdfVishay SFH61366http://www.vishay.com/docs/83668/sfh6135.pdfMCU:Microchip PIC16F877A2Relays:China Power JQX-105F-14https://www.futurlec.com/Datasheet/Relays/JQX-105F.pdfAxicom D2n V231051http://www.te.com/commerce/DocumentDelivery/DDEController?Action=showdoc&DocId=Specification+Or+Standard%7F108-98007%7FG%7Fpdf%7FEnglish%7FENG_SS_108-98007_G.pdf%7F8-1393792-5OpAmps:TI TLV27701http://www.ti.com/lit/ds/symlink/tlv2770.pdfOnSemi MC33171P2https://www.futurlec.com/Datasheet/Motorola/MC33171.pdfThere's also 4 IRF 4905 MOSFETs. Interestingly the Vishay SFH6136 Optocouplers that have the red coating on them are high speed optocouplers. I'm not sure why that would necessitate a coating unless there was concern that something might touch them and interfere with the communication.I will at some point trace out the connections to the 15pin port. There are at least 2 maybe 3 wires that go from 1 PIC to the other so possibly some kind of communications bus. There's no RS232 or other serial controllers on the board, but I assume it is possible for it to be done inside the PIC and go through the optocouplers to the outside world. The PIC towards the top is wired to all the LEDS and I think the one at the bottom is wired to all the relays.

author: Vgkid
author_rank: Super Contributor
timestamp: December 29, 2014, 07:54:27 am
content: What are the flat square yellow components?

author: Stonent
author_rank: Super Contributor
timestamp: December 29, 2014, 08:11:39 am
content: Quote from: Vgkid on December 29, 2014, 07:54:27 amThey are Raychem 30 U900 PTCshttp://www.mouser.com/ProductDetail/TE-Connectivity-Raychem/RUE900/?qs=QV10cN0MjFvPR2FscNF6Ow%3D%3D3 say China on the back and 1 says Mexico.These appear to be designed to run at 9 Amps continuous and will trip at 18 Amps if it exceeds 20 seconds.