DN Staff

June 27, 2005

2 Min Read
Guido Had a Strong Aversion to Overbrewed Oolong

For Guido Vollmar's complete instructions on how to build your automatic tea timer, click here. To view pictures and a schematic diagram of the tea timer, click here.

In search of the perfect cuppa, Guido engineered this simple, battery-operated tea timer with a built-in LED display. Just fix a tea-bag on the mechanism's extension arm, place a cup of hot water beneath it, and push a button according to the desired brew time. The microcontroller-operated, 5V circuit provides a servo motor with control pulses to lower and raise the extension arm. The brew process can be interrupted via a stop button, while the power supply is switched off automatically via FET.

Tea Timer Parts List

Amt

Part Description

Allied Part #

1

9V Battery

737-0530

2

100 nF Capacitor

881-5228

1

330 pF Capacitor

881-5182

1

10 muF Capacitor

852-7072

1

470 muF Capacitor

852-6592

2

BAV 100 Diode

431-0452

1

400 mA Fuse

740-5209

2

Fuse Clips

846-6062

1

LM317T

288-1251

1

Yellow LED

782-0040

1

NC Slider

870-9934

4

NO Push Button

948-7199

1

Transistor BC846

263-0418

1

Si 9430DY MOSFET

307-1057

Additional parts required: IC1 PIC: 16C54; Servo motor like used in RC-toys; Old cookie box or similar package as housing; Short piece of wood for extension arm; Screws for mounting servo and protoboard; Assorted resistors (see detailed parts list online); Protoboard; Battery holder

Sign up for the Design News Daily newsletter.

You May Also Like