Graymark 808 User Manual

Explains Graymark's Self-Tech system for building the project, focusing on educational value and step-by-step construction.

Provides assembly instructions without electronics theory, for those not needing educational content.

Lists and describes the essential tools recommended for kit construction to ensure proper assembly and prevent damage.

Provides detailed rules and techniques for making proper solder connections, emphasizing safety and quality.

Presents the electrical schematic diagram of the Graymark 808 Power Supply, detailing component connections and layout.

Illustrates the functional relationships between the major circuit blocks of the 808 Power Supply.

Explains how factors like skin moisture and breaks affect body resistance to electricity, influencing shock severity.

Outlines essential safety precautions for working with electronic circuits to prevent injury and equipment damage.

Provides nine essential rules for successful and enjoyable assembly of the power supply/breadboard kit.

Describes a crucial initial test to check for incorrect component installation or defects by briefly powering the unit.

Explains how to use an ohmmeter to measure resistance on components, noting polarity considerations for diodes.

Highlights the importance of PCBs in modern electronics and the role of the PCB in the 808 Power Supply assembly.

Explains how electronic circuits are illustrated using schematic and block diagrams.

Details the components of the input circuitry, including the AC power cord, fuse, and power switch.

Introduces the transformer as an AC device that transfers electrical energy, explaining its basic form and function.

Explains the principle of mutual induction based on Faraday's Law, crucial for transformer operation.

Describes different transformer winding configurations like one-to-one, step-up, and step-down.

Provides formulas and examples for calculating secondary coil voltages based on transformer turns.

Outlines common transformer faults and the methods for detecting them using an ohmmeter.

Details the procedure for testing transformer windings for continuity and correct lead wire color coding using a VOM or DMM.

Describes how to test transformer windings for electrical isolation from each other and from the core using an ohmmeter.

Guides the user through installing the power switch and verifying its correct operation.

Instructs on mounting the fuse holder and connecting the AC power cord to the input circuitry.

Provides steps to verify the correct wiring of the power switch, fuse holder, and AC power cord.

Guides the installation of the AC power cord grommet in the rear of the cabinet for strain relief.

Details the insertion and soldering of test points and transformer leads onto the PCB.

Explains the difference between DC and AC voltage representation on graphs and the need for an oscilloscope for AC.

Provides a procedure to observe and measure peak, peak-to-peak, and RMS AC voltages using an oscilloscope and VOM/DMM.

Introduces the three basic types of rectifier circuits (half-wave, full-wave center-tapped, full-wave bridge) and their characteristics.

Discusses the application of half-wave rectifiers and introduces the half-wave rectifier test.

Illustrates the schematic diagrams for half-wave, center-tapped full-wave, and full-wave bridge rectifier circuits.

Provides a table comparing the characteristics of different rectifier circuits, including diodes, current, ripple, and efficiency.

Guides users to observe a diode's current blocking capability using a VOM/DMM.

Details how to observe the voltage waveform produced by a half-wave rectifier circuit using an oscilloscope.

Explains the requirement of a center-tapped transformer for this rectifier type and its use in the 808 Power Supply.

Guides users to observe the voltage waveform from a full-wave center-tapped rectifier circuit using an oscilloscope.

Discusses the efficiency and cost-effectiveness of full-wave bridge rectifiers in power supplies.

Details how to observe the voltage waveform produced by a full-wave bridge rectifier circuit using an oscilloscope.

Explains how this circuit combines features of center-tapped and bridge rectifiers and its output polarity.

Guides users to observe the voltage and waveforms from a full-wave center-tapped bridge rectifier circuit.

Defines filters and lists four common types (low pass, high pass, bandpass, bandstop) used in electronics.

Explains the use of RC filters to remove ripple from rectifier output and the role of resistors and capacitors.

Explains ripple percentage and provides a formula to calculate it from voltage measurements.

Details the process of determining the necessary filter capacitance based on output requirements and calculations.

Explains the concept of time constant for capacitor discharge and provides relevant formulas and a graph.

Guides users to observe the action of an actual RC circuit using a power supply, VOM/DMM, and timer.

Details mounting capacitors and resistors on the PCB to serve as bleeder resistors and for filtering.

Outlines a series of tests to verify the correct assembly of the PCB components and check for proper operation.

Introduces the three voltage regulators (LM317, LM337, LM309) used in the 808 and their functions.

Provides detailed electrical specifications and maximum ratings for the LM317 adjustable positive voltage regulator.

Details the electrical specifications and maximum ratings for the LM337 adjustable negative voltage regulator.

Guides the installation of the LM317 voltage regulator, heat sink, and associated components on the PCB.

Outlines the procedure to test the installed +15V regulator, checking for heat and measuring output voltage.

Details the installation of the LM337 voltage regulator, heat sink, and related components on the PCB.

Describes the steps to test the installed -15V regulator, checking for heat and measuring its output voltage.

Guides the installation of the LM309 voltage regulator, large heat sink, and components onto the PCB.

Outlines the procedure to test the installed +5V regulator, checking for heat and measuring output voltage.

Explains the need for regulation and defines Load and Line regulation for power supplies.

Defines load regulation and contrasts the behavior of regulated vs. unregulated power supplies under varying loads.

Defines line regulation and illustrates its effect on power supply output voltage with changing AC line voltage.

Discusses the effect of load changes on regulator output and the role of protection circuitry.

Guides users to observe the operation of the external overcurrent limiting function of a voltage regulator.

Explains how voltage regulators can overheat and how protection circuitry prevents damage.

Details how to observe a voltage regulator's behavior when it enters over-temperature protection mode.

Introduces the circuitry for controlling the adjustable voltage outputs of the power supply.

Guides users to demonstrate how adjustable regulator output responds to different voltages at the adjustment terminal.

Explains the external protection circuitry designed to prevent damage to other power supply components.

Details the mounting of resistors and transistors for the external protection circuitry.

Outlines tests to verify the correct installation and basic operation of the external protection circuitry.

Guides users to demonstrate the external overcurrent protection circuitry by creating a load condition.

Details connecting potentiometers to the PCB for external voltage control adjustments.

Guides users to test the functionality of the external voltage control circuitry by adjusting output voltages.

Guides the final connections and wiring to the test points on the assembled PCB.

Instructs on attaching rubber feet to the cabinet bottom for stability.

Details mounting the breadboard and bus strip to the cabinet top using screws.

Guides the mounting of the power transformer to the cabinet bottom and its electrical connection to the PCB.

Guides the process of joining the cabinet top and bottom halves, ensuring wires are not pinched.

Details installing and tightening screws to secure the cabinet halves together.

Provides a comprehensive procedure to verify that all three power supplies are working correctly after assembly.

Explains how the breadboard's holes are interconnected, detailing bus strips and component sections for circuit construction.

Outlines a three-step process for isolating and resolving problems if the project does not operate correctly.

Lists all test points (TP#) on the PCB and provides a brief description of what each point represents.

Shows transformer specifications including winding resistances and lead color codes.

Provides pinout diagrams for the LM317, LM337, and LM309 regulators, and common transistors.

Explains how to read resistor values using both four-band and five-band color codes.

Summarizes the theoretical concepts and practical skills gained from building the project.

Lists the key specifications of the Graymark 808 Power Supply, including power source and output ratings.

Provides instructions for ordering replacement parts, including necessary information and payment methods.

Outlines Graymark's policy for inspecting and repairing malfunctioning projects.

Details Graymark's warranty terms, limitations, and conditions for their electronic projects.

Promotes other available Graymark electronic kits and provides contact information for their catalog.