add mob-audio-*

CHANGES.md

@@ -2,6 +2,12 @@
 This file contains the log of changes of **MOBs Library** project.
 
 
+## 0.7.0 2024-07-21 Feature release
+- Added MOB mob-audio-psu-9v-5v
+- Added MOB mob-audio-jack
+- Added MOB mob-audio-io-stage
+
+
 ## 0.6.0 2024-07-04 Feature release
 - Added MOB mob-voltage-divider-pot-2x
 

README.md

@@ -4,6 +4,7 @@ Various modular-designed electronics boards created for home learning projects.
 ![overview](images/overview.jpg)
 
 These MOdule Boards (MOBs) are useful for:
+* doing experiences
 * testing specific components functions
 * prototyping complex projects by modular approach
 * expanding and interfacing components functions
@@ -29,6 +30,12 @@ These MOdule Boards (MOBs) are useful for:
 * [mob-if-rs232](mobs/mob-if-rs232/) : rs232 interface board
 * [mob-mcu-pic16f6x8](mobs/mob-mcu-pic16f6x8/) : Microchip PIC 16F6x8 microcontroller module board
 
+### MOBs for audio experiences
+* [mob-audio-psu-9v-5v](mobs/mob-audio-psu-9v-5v/) : psu 9V (VCC) and 5V (VR) module board
+* [mob-audio-jack](mobs/mob-audio-jack/) : audio TRS jack 1/4" adapter module board
+* [mob-audio-io-stage](mobs/mob-audio-io-stage/) : audio input and output stages module board
+
+
 ## Specifications
 Schematics and PCB layouts are designed with ExpressPCB free CAD software.
 

mobs/mob-audio-io-stage/README.md

@@ -0,0 +1,32 @@
+# *Audio I/O Stage* Module Board
+Audio input and output stages module board.
+This MOB operates at 9V or more for VCC (rail voltage of op-amps) and VCC/2 for internal VR (reference voltage for virtual ground).
+The input is a buffer stage, the output stage has a selectable gain (jumper JSW2) between 1:1 or 2:1.
+
+![mob-built](mob-audio-io-stage_built.jpg)
+
+
+## Schematic
+![mob-schematic](mob-audio-io-stage_sch.jpg)
+
+
+## PCB Layout
+![mob-pcb](mob-audio-io-stage_pcb.jpg)
+
+
+## Bill of Materials
+- [x] paperboard 5x7cm
+- [x] 2-pin (Molex-KK) VCC-GND power connector
+- [x] 2-pin (Molex-KK) external VS-GND power connector
+- [x] 4 x 2-pin (Molex-KK) input/output audio connector
+- [x] 2 x bulk capacitor (tantalum) 10uF
+- [x] 2 x led current limiter resistor 2K2Kohm and 1Kohm
+- [x] 2 x power activity led green 3mm
+- [x] 3-pin voltage VS internal/external selector header
+- [x] 3-pin output gain selector header
+
+- [x] 9 x resistors: 1 x 1Mohm, 2 x 470Kohm, 1 x 100Kohm, 4 x 47Kohm, 1 x 100ohm
+- [x] 1 x decoupling capacitor C=100nF
+- [x] 1 x bulk capacitor 47uF
+- [x] 5 x filter capacitor 1 x 10uF, 3 x 1uF, 1 x 4n7F
+- [x] IC Dual OpAmp NE5532 with socket DIP4+4

mobs/mob-audio-jack/README.md

@@ -0,0 +1,22 @@
+# *Audio Jack* Module Board
+Audio TRS jack 1/4" (T = Tip, R = Ring, S = Sleve) connectors module board.
+
+
+![mob-built](mob-audio-jack_built.jpg)
+
+
+## Schematic
+![mob-schematic](mob-audio-jack_sch.jpg)
+
+
+## PCB Layout
+![mob-pcb](mob-audio-jack_pcb.jpg)
+
+
+## Bill of Materials
+- [x] paperboard 5x7cm
+- [x] 2 x Connector Jack TRS 6-pin
+- [x] 2 x 2-pin (Molex-KK) audio mono connector
+- [x] 2 x 3-pin (Molex-KK) audio stereo connector
+- [x] 2 x 3-pin TRS L+R/L+L selector header
+- [x] 4 x bypass capacitor 4u7F

mobs/mob-audio-psu-9v-5v/README.md

@@ -0,0 +1,29 @@
+# *Audio PSU 9V 5V* Module Board
+9V (VCC), 5V (VR) psu module board.
+
+PSU module for the power supply of the analog audio MOBs operating at VCC=9V and VR=5V.
+The module can be powered from 12V to 15V AC or DC, provides stabilized output and delivers a maximum current of about 0.5A.
+
+![mob-built](mob-audio-psu-9v-5v_built.jpg)
+
+
+## Schematic
+![mob-schematic](mob-audio-psu-9v-5v_sch.jpg)
+
+
+## PCB Layout
+![mob-pcb](mob-audio-psu-9v-5v_pcb.jpg)
+
+
+## Bill of Materials
+- [x] paperboard 5x7cm
+- [x] 5.1 power jack connector
+- [x] 3 x led current limiter resistor: 1 x 1Kohm, 2 x 2K2ohm
+- [x] 3 x power activity led green 3mm
+- [x] 4 x 2-pin (Molex-KK or KF2510) power connector
+- [x] filter capacitor 1000uF
+- [x] 4 x capacitor 100nF
+- [x] 1A diodes bridge
+- [x] 7809 voltage regulator TO220 package
+- [x] 7805 voltage regulator TO220 package
+- [x] 2 x pcb switch