Ramsey Electronics manual DN1 Circuit Description

We designed our kit to change quickly and easily adapt to a variety of cell or battery pack types for anything from video camcorders to cordless phones. You can configure it for the number of batteries in your pack, discharge and charging rate. We’ll discuss this later as we’re assembling these sections of the circuit.

DN1 CIRCUIT DESCRIPTION

Before we get into the technical jargon, let’s take a walk around the BQ2003 Integrated Circuit . We’ll start with some definitions of the abbreviations written on the chip in the schematic diagram.

Benchmark BQ2003 pin designations:

Pin No.	Abbreviation	Function
1	CCMD	Charge command
2	DCMD	Discharge Before Charge Command
3	DVEN	- ∆V Enable Input
4,5	TM1 & 2	Timer Mode Outputs
7	BAT	Single Cell Voltage Input
8	VSS	Ground
9	SNS	Charging Current Sense Input
11	MCV	Maximum Cell Voltage Reference
13	CHG	Charging Status LED Output
14	MOD	Current Switching Control Output
15	DIS	Discharge Control Output

16

VCC

5 Volt input

The BQ2003 charger IC handles many of the functions related to our charger. Without trying to sound too much like a technical manual or data book, here’s a closer look at some of the accompanying circuitry. Have a glance at the schematic diagram and follow along.

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