It is called analog dial timer as it has no digital display, but the chip is digital it is CD4541. It is Mains operated, you could make on-delay or off-delay. By changing the caps and resistors or with even dip-switches you could get timing of few seconds to many hours. Circuit is Analog Timer 4541 .
Some timers energize the relay after a set delay on power start. Some start with relay energized and turn off after set time. Motors and big systems cannot take fast turn-on and turn-off, Some systems will require sections or modules to start one after another as they are interdependent.
This is in continuation of the thread called "Design of a Thermocouple Amplifier" doc00023.html which is in the same section .
This is just a formatted-edited email thread exported from Eudora from my mailbox using the content concentrator. The circuits below were made by TF a student, This thread has been put online to share information.
The part under "From: delabs" are my writing. there may be some mistakes and broken links.
"In order to communicate effectively, humans developed languages, signs and writing; however, communicating over long distances has always been a slow process…"
"Some African tribes still use drums to send messages across the savanna."
"On May 24th, 1844, an American artist and inventor called Samuel Morse (1791-1872) sent the first telegraph message from the Supreme Court Chamber of the U.S. Capitol Building in Washington D.C. to a receiver in Baltimore, some 65 km away."
"Thomas Doolittle developed a new process to draw strong copper wire. Because of its better electrical conductivity over iron, copper wires became the standard in telephony."
This course is designed to help you learn about components, circuits, and the use of electronics. You can explore the contents in whatever order you wish.The emphasis is on providing information starting at the 'absolute beginners' level, but we hope eventually to provide material of use to anyone interested in electronics and its applications ...
This section of the Scots Guide deals with Analogue Electronics with a special emphasis on Audio-related topics. There are also some specialist pages on the properties of cables as these relate to audio.
The First Eleven - Basic electronics courses sometimes make it appear as if electronic engineers have an obsession with voltmeters, batteries, and oscilloscopes. That's because it's often convenient to talk about these when presenting a course at a university, college, or wherever. In reality, the physics and electronics of practical systems like Hi-Fi's, TV's, computers, etc, are much more interesting.
The main components used in electronics are of two general types: passive (e.g. resistors and capacitors) and active (e.g. transistors and integrated circuits). The main difference between active and passive components is that active ones require to be powered in some way to make them work. Active components can also be used to amplify signals.
by J. C. G. Lesurf University of St Andrews Astronomy Group, Scotland.