Relay Help

What is it that you wish you know? If you take a few moments to review all the last post in this forum. You will have alot of basic understanding of how, and when to apply the relay. If there are specific question as to what you want to know, please ask. But, understand there are alot of answers already indicated within the forum you are in now. Regards EVIL Teken . . .

if you really want to see how they work open one up and look at the coil and the contacts, move the contacts and see the outcome...

Here are the most basic things you need to know about relay(s). 1. There are two types of relays: electromechanical (EMR) & solid state relays (SSR). Both serve the same basic function as a on / off switch. 2. Relays are used for two basic purposes: To use a small voltage to turn on or off a larger current / voltage device(s). A relay is used to isolate two components, so as there is no interaction between the two. 3. To activate a relay the coil, which is pin 85 & 86 must have proper polarity apllied to it. ie. One side of the coil must be positive (+), and the other must be negative (-). 4. There are technically only (2) contacts, which are pins 87 and 87a. Pin 87 is normally open (N.O.) and pin 87a is normally closed (N.C.) The relay at rest (not energised / turned on) is always in contact with pin 87a. When the coil is activated by the proper voltage, the arm of the relay will move over to pin 87, so long as there is voltage applied. Pin 30 is common pin which contacts either pin 87 / 87a depending upon the condition of voltage applied. 5. Apply / install the correct amperage relay by knowing the current draw / demand of the circuit required. Simply by adding the current draw from the literature will give you a base line to shoot for. Technically speaking it is advised that you actually measure the current draw in series of the circuit to be activated / interuppted. 6. The power (source) side of the relay must always be fused. 7. A quenching / de-spiking diode is placed across the coil (85-86) of the relay to prevent Counter Electro Magnetic Force (CEMF) from damaging sensitive electronics. ie. This can be considered a spike, surge, or leakage of current / voltage. When a diode is incorporated into the relay proper polarity must be observed, other wise the diode will fail. 8. Every relay has a specified pick-up and drop out voltage. Both dictate when the relay will turn on or off based on the thresh-hold of voltage present, or not. 9. If you are not well versed in crimping, always use and apply the 5 pin female wired plug to the relay. This will ensure 100% contact, and avoid problems due to improper termination of the plugs to the pins. 10. You must only install relays for interioer use. Unless the relay has been so designed with a weather cap in the casing. Even then, the exterior relay is also filled with grease to prevent moisture from affecting the operation of the relay. Regards EVIL Teken

I would encourage you take the time to read over as many of the older posts in this forum. Also, take the time to actually play with one. There are three types of brains *learning behaviour*. 1. Spacial: Persons in question can imagine and comprehend by verbal and pictorial methods. This accounts for 30% of those people in the world. 2. Physical: Persons learn by doing the actual task required. It is the actual physical interaction that ingrains the knowledge upon the persons synaptic brain paths. 45% of the population fall into this catogory and only fully learn and comprehend what is being taught by doing the actual deed / task. 3. Moderate: The remaining 25% of the population have a common balance of sight and feel in the learning process. At the end of the day, ask questions. But, temper those questions with *thinking* about the possible answers and how they came to be. There is never a stupid question. Only the one you don't ask which results in damage, and loss of time to the project you wish to complete. Regards EVIL Teken . . .