Diagram Diagosis

This electrical troubleshooting manual is divided into following sections: Index, How to Use the Wiring Diagram, Wire Size and Conversion Chart, Symbols, Systematic Troubleshooting, Connectors Views, Power Distribution Box, Fuse Data, Component Location Chart and Views, and Splice Location Views. Further breakdown, this manual covers topics on operation description and systematic troubleshooting for power distribution system, charge and starting system, ABS, Brake Warning System, Power Mirrors, Central Locking, Power Windows, electronics fuel injection system, SRS, Seats, Electro-Mechanical Convertible Top, Body Electrical System, Wiper and Washer, Instrument Cluster, etc.

All wirings and the wiring between components are shown exactly as it exists in the vehicle; but, the wiring is not drawn to scale. Wiring inside complicated components has been simplified to solid state label designates electronic components to help you in understanding the electrical operation,

A complete troubleshooting manual for the 1992 BMW 325i Convertible Electrical Troubleshooting Manual is here – 142 pages of PDF file.

Output power: 6W into 4 Ohm load, FET input stage - Passive Tone Control

Tiny, portable Guitar Amplifiers are useful for practice on the go and in bedroom/living room environment. Usually, they can be battery powered and feature a headphone output. This project is formed by an FET input circuitry, featuring a High/Low sensitivity switch, followed by a passive Tone Control circuit suitable to Guitar or Bass. After the Volume control, a 6W IC power amplifier follows, powered by a 12-14V dc external supply Adaptor or from batteries, and driving a 4 Ohm 10 or 13cm (4"/5") diameter car loudspeaker. Private listening by means of headphones is also possible.

Circuit diagram:
Parts:

P1______________1M Linear Potentiometer
P2____________100K Log Potentiometer
R1_____________68K 1/4W Resistor
R2____________470K 1/4W Resistor
R3______________2K7 1/4W Resistor
R4______________8K2 1/4W Resistor
R5____________680R 1/4W Resistor
R6____________220K 1/4W Resistor
R7_____________39R 1/4W Resistor
R8______________2R2 1/4W Resistor
R9____________220R 1/4W Resistor
R10_____________1R 1/4W Resistor
R11___________100R 1/2W Resistor
R12_____________1K5 1/4W Resistor
C1____________100pF 63V Polystyrene or Ceramic Capacitor
C2,C5,C9,C14__100nF 63V Polyester Capacitors
C3____________100µF 25V Electrolytic Capacitor
C4_____________47µF 25V Electrolytic Capacitor
C6______________4n7 63V Polyester Capacitor
C7____________470pF 63V Polystyrene or Ceramic Capacitor
C8______________2µ2 25V Electrolytic Capacitor
C10___________470µF 25V Electrolytic Capacitor
C11____________22nF 63V Polyester Capacitor
C12__________2200µF 25V Electrolytic Capacitor
C13__________1000µF 25V Electrolytic Capacitor
D1______________3mm red LED
Q1____________BF245 or 2N3819 General-purpose N-Channel FET
IC1_________TDA2003 10W Car Radio Audio Amplifier IC
SW1,SW2________SPST toggle or slide Switches
J1____________6.3mm Mono Jack socket
J2____________6.3mm Stereo Jack socket (switched)
J3_____________Mini DC Power Socket
SPKR__________4 Ohm Car Loudspeaker 100 or 130mm diameter

Notes:

• Connect the output Plug of a 12 - 14V dc 500mA Power Supply Adaptor to J3
• Please note that if the voltage supply will exceed 18V dc the IC will shut down automatically

Technical data:

Output power (1KHz sinewave):
6W RMS into 4 Ohm at 14.4V supply
Sensitivity:
50mV RMS input for full output
Frequency response:
25Hz to 20kHz -3dB with the cursor of P1 in center position
Total harmonic distortion:
0.05 - 4.5W RMS: 0.15% 6W RMS: 10%

Tone Control Frequency Response:

This is a design circuit of board system monitoring for temperature and voltage condition. This circuit uses the NE1617A. The NE1617A is a 2 channel temperature sensor. It can measure remote and internal sensor. It also supports up to nine devices per bus. The temperature data update is selectable from 125 ms to 16 seconds, if it is used in normal operation. An internal, the temperature reading can be forced by one-shot command. This is the figure of the circuit.

The advantage of the NE1617A is programmable, has high accuracy, small, 16-pin QSOP packages and has an operating temperature of 0 to 120 °C. It can be used for applications where thermal monitoring of electrical components and hardware is critical. The more advanced version of the NE1617A is the NE1619. Besides measures the remote and internal temperature, the NE1619 can be used to monitor nine different voltages. It has programmable voltage  and temperature limits for controlling internal alarms and  supports two devices per bus. It also has an on-chip A/D converter which supports data collection and other functions. The consistent conversion rate that is used by the NE1619 is approximately 500 ms. [Circuit schematic source:  NXP Application Note]