One Knob Fuzz board with expanded pin options for alternate NPN transistor pinouts. rev2: removed +9v pour

ELM440_Timebase-6/board

A USB C breakout board for TYPE-C-31-M-12 connectors

3M Textool ZIF PLCC84 socket for easily checking/flashing EPM7128S and EPM7160S CPLD devices. (Many from eBay have JTAG disabled - this is to test them without soldering!)

R1/D1 are LED and bias R2-R5 are 1K C1 is 33uF 6.3mm cap C2-C7 are 100nF U1 is AP1117-5.0v reg D1 is any 1A rectifier J1 is PJ-102

“Current” jumper must be shunted or connect to DC Ammeter

Use with Altera USB blaster and Quartus

UNTESTED Latching Quad Kickstart Switcher for Amiga 500+ Rev 1.2002. As with other quad switchers, this also selects between 4 512KB banks from M27C160 using JP0 & JP1 to pull high address lines A18 & A19 high, respectively. The unique feature of this switch is that it will not actually switch to a new bank until after the keyboard reset signal (connect to ~ROM_KBRESET) is finished asserting low. This prevents switching during normal operation from changing the active ROM image while it is in use.

BOM: - (ROM_U1) 1x 42-pin DIL socket (and programmed M27C160 EPROM) - (ROM_A1) 2x 1x20 turned pin headers for the bottom of the board. - (ROM_U2) 1x 74AHC273 or equivalent octal latching D-type flipflop IC. - (R1) 1x 1k axial resistor. - (R2-3) 2x 4k7 axial resistor. (Small enough to fit under the M27C160 after it is installed in the socket.) - (C1) 1x 10pF bipolar small axial cap for power-up reset delay. - (C2) 1x 0.1uF bipolar small axial cap for bypass.

Link to project will be included when it is available.

See the Github project page for the BOM and the software. Use this board to add automatic audio signal sensing to your Bose Cinemate GS Series II speakers.

This board uses terminal blocks so that the end user doesn’t have to use a soldering iron to change pickups in their 3 pickup 5 way switch equipped guitars.

Digital Panel Meter with divider

BOM

Contact me if there are questions.

The reason for this Project was the tiny output of my old detector radios which had to be substantially enhanced .

To keep it simple I just wanted to use an opamp to increase the volume by a factor of say 100. Audio signals, however, carry positive and negative voltage levels which means that the opamp had to be provided with both a positive and a negative power rail. I don’t like having two batteries in my design and so I had to find a way to correlate the 0V level of the audio signal to the midst of the available battery voltage.

It is easy to use a voltage divider to generate that mid voltage. However, you can’t tap any power from it without having the tapped voltage wander off because the load circuit changes the resistance ratio of the voltage divider. This means that somehow the tapped voltage has to be stabilized. One way to achieve this is an additional opamp which acts as a Buffer, which is why a dual opamp would come in handy. The Analog Devices AD8034 is rail-to-rail and has more than enough of a voltage range.

The PCB offers enough real estate to use 0805 parts and a SOIC-8 chip. I went for 0603 parts and a SOT-23-8 chip instead because there are so few components on this board that its assembly serves as a nice study in soldering smaller structures.

Schematics:

3D Model:

BLE SOC[pls ignore silkscrn err, hope .drl file OK]

Beehive temp/humidity/weight with ESP8266 12F