View allAll Photos Tagged PCB
This PCB connects the modem to the telephone line. It contains the isoating transformer, a circuit to pass the line hold current and 3 relays which are basically equivalent to the gravity switch (hook switch), dial off-normal, and dial impulse contacts of a rotary dial
telephone.
The green LED is labelled 'Carrier' on the front panel. It is nothing of the sort. It simply indicates when the gravity switch relay is energised and the unit is thus conneted to the telephone line.
The telephone line cable plugs into the 7 pin header in the front middle of the board. Only 4 pins are used. 2 for the line, 2 for a relay contact to disconnect the associated telephone. This is the standard (for the time) Viewdata set wiring.
This is one of the first pcb's i made. It's made with a 60 degree carbide v-cutter. The traces are 0.2mm wide and 0.1mm deep. The holes are 1mm dia. The layout is made with eagle and the pcb-gcode script.
Populated with resistor, capacitors, MAX7219 chip and connectors. The four diagonally-mounted four-pin connectors mate with the pins on the back of the main LED matrix PCB.
Edging on panels are scraped off
All panels in order had edges like this.
Thanks Hackvana for this crap job and for not doing anything about the QA issues
A PCB by Jared Boone, photo shared with permission.
Jared says:
"The board is a breakout to connect a Linear Technology LT228x/9x high-speed analog-to-digital converter IC to my Digilent NEXYS2 FPGA development board. I'm planning to digitize lots of RF signals soon... Symmetry is important in this design, because this board captures signals in quadrature (a neat trick to simplify anti-alias filtering of the signal you want to digitize). You can also see that I've separated the ground plane into two regions -- this helps keep the digital noise of the digitized data from coupling back into the converter inputs and adding noise to the data I'm capturing."
Milled PCB for 5v power supply using wide 50 mil traces with 34 mill of trace cut on double sided copper PCB blank.
Hitachi PCB 0A30652 (PCB Swap, PCB Replacement, PCB Logic Board Sale, Buy PCB Circuit Board - HDDZone.com)
The unit consists of a 3-stage transistor amplifier on this PCB. The 3 transistors are the red-sleeved components (type GET113, Germanium PNP).
Left: populated completely. 20 components (excluding pin headers and the jack).
Right: bare bones, minimal components: no polarity protection, LEDs, voltage regulation, analog reference (cap), ICSP header, or I2C header. 6 components (excluding pin headers and screw terminals).
More info on my blog: