Chargers

5 W charger embedded in system board charges capacitor bank for a pulse amplifier supply.

At the core of capacitance-bank and battery chargers are switching power converters. They are found in pulsed power equipment, such as pyrotechnic pulse generators, magnetizers, photoflash units, pulsed lasers, and analytic instruments.

5 W Variable-Frequency Flyback Charger Technical Report

	Charger circuit schematic diagram, in HTML
	75 v and 160 V charger design programs, in HTML and MathCAD
	Charger Circuit Design - detailed explanations and derived design equations for fixed and variable frequency, DCM and CCM chargers

5 W Charger Features

	Variable-frequency flyback converters adapt off-time to C-bank voltage for faster charging
	Isolated C-banks charged to 75 V and 160 V; design modification of magnetics for other voltages
	Input supply is +5V at less than 600 mA average, 3 A peak for DCM design
	Uses two low-cost ICs: 555 timer and LM339 quad comparator
	DC or PWM analog input voltage commands output charging voltage
	Microcontroller-compatible interface bit-line indicates when charged; another bit-line turns charger on/off

The low-power 5 W flyback charger is an example of the kind of chargers described in the 16-page section on CCM and DCM flyback charger circuit design. Topics include:

	Flyback converters
	Minimum-time continuous-current (CCM) charger design
	Converter control, duty-ratio range, and turns ratio
	Current ratcheting at low output voltage
	Variable-frequency de-ratcheting
	Charger off-time as a function of output voltage
	Off-time generator circuit
	Variable-frequency charging time
	Inductor design
	Fixed-frequency charger design
	CCM and DCM charging dynamics
	Time-averaged versus voltage-range-averaged currents
	75V- and 160 V-output designs include MathCAD design programs

750 W Half-Bridge Zero-Power-Switching Charger Technical Report

This low-loss half-bridge charger topology originated at Innovatia and extensively employs zero-power switching in both primary and secondary circuits. The 750 W converter design is applied to capacitance-discharge applications. The high-power 750 W charger was designed to charge a capacitance bank for SCR discharge into magnetizing fixtures, for spot welding, or for other high-current pulse applications. At higher power, second-order design effects become significant. These are explained, along with the converter topologies, which converter topologies not to use, and why.

Background

	Switching Converter Configurations
	Transistor-Switch Analogs
	Converter Switch Model

ZPS Half-Bridge Converter

	750 W ZPS Converter Charger Circuit Diagram
	Half-Bridge Circuit Behavior
	Half-Bridge Flux-Charge Stability
	ZCS Secondary Circuit
	ZPS Half-Bridge Charger

750 W Charger

	Single-board capacitance-bank charger, plus isolated SCR firing circuit
	Variable-voltage (up to 750 V), 2 A (750 W average) half-bridge converter design
	Charger and firing control circuits; PAL design file is included in designware license package
	Example design operates from 120 V ac line
	High-power SCR discharge circuit (system) design
	Peak-current detector circuit
	Current- versus voltage-mode control, and magnetics and secondary-circuit problems to avoid
	Converter circuit design explained in detail, including gate drivers, magnetics, control loop, logic circuits, and forward converter

Charger Ordering

5 W Variable-Frequency Flyback Charger Design Tech Report
750 W Innovatia ZPS Half-Bridge Charger Design Tech Report

Ordering Information

5 W Charger Designware License: Inquire.

750 W Charger Designware License: Inquire.

Designware license price is one-time license fee (includes applicable deliverables).