This project is a timer project and build around popular 555 Timer IC, It can be used for all application required a delay of up to 100 Seconds. Onboard board preset to adjust the required timer duration in range of of 1 to 100 Seconds, Tact switch SW1 to reset the timer and SW2 to start the timer. LED D3 works as power indicator and LED D2 to indicate timer operation.
Load can be connected to CN1 Screw Terminal, Out-put has both the operation normally Open and normally closed. Circuits works on 12V DC and consume approx. 100mA current. Very useful project can be used in various applications like water irrigation system, Kitchen timer etc.
Supply input 12 VDC @ 100 mA
Onboard start and reset tactile switch
Relay output: SPDT relay
Relay specification: 5 A @ 250 VAC
Relay state LED indicator
Preset adjustable range function
Power-On LED indicator
Screw terminal connector for easy relay output connection
Four mounting holes of 3.2 mm each
PCB dimensions 48 mm x 63 mm
1 to 100 Seconds Timer - [Link]
Compact installation step relays Finder 26 series save energy similarly like latching relays, but they also operate on AC voltage.
Step relays are able to effectively control lighting or other devices and they significantly simplify circuit complexity at the same time. If you´re familiar with a bistable (latching) relay, then you know, that a relay can keep its status (On/Off) even without a power supply. A step relay, which we´d like to introduce to you this time, is mechanically significantly different from latching relays, but it also features this energy-saving property – i.e. maintaining the On/Off status even without a power supply.
A step relay is usually available with an AC coil and it´s very simply controllable by one push-button switch (momentary SPST-NO). The principle of the step relay is in the fact, that a driving coil mechanically moves a contact mechanism in various sequences. Each switching of a relay (switching a power to a coil) moves a mechanism in one “step” further. In the simplest case the sequence looks as On/Off/On/… But it also can be in other way, as illustrated in the attached picture. Step relay are probably the most frequently used for switching of lighting. This is enabled by a fact, that simple push-button switches, controlling a coil, are connected in parallel. In result, the circuitry gets much simpler and to control one or two lighting circuits from several places, it´s necessary to use only 2 wires (moreover only with a small cross-section – say 0,5mm2). Second saving is in a practically zero power consumption of the relay itself, as energy is only necessary to change a relay status.
Finder 26 series is constructed as a “small box”, which can be placed on a panel but also for example – into a common wall installation enclosure. On stock we keep the type 26.02.8.230.0000, what´s a two-pole (10A) relay with 230Vac coil, with the On/Off sequence. Upon order, we´re able to supply you also versions with 12/24/48/110Vac coils and also modules for usage with 12/24VDC and for usage with illuminated switches.
Detailed information and a comprehensive table about possibilities of usage of particular types will provide you the Finder 26 datasheet. Useful examples of usage of these and also other switching components from Finder will provide you the document „Finder – The Electrician´s guide”.
With a step relay Finder 26 can be saved energy and also installation costs - [Link]
Kerry Wong writes:
Latching relay (a.k.a. impulse relay) can be turned on and off by momentarily applying a voltage across the relay coil. The relay would maintain in its last switched state without the need to maintain the coil current. In this post, I will show a simple circuit which can be used to drive such relays. In the video towards the end, I also included more explanations and some demonstrations.
The relay I am using here is a latching RF relay. It is used to switch the input signal between its two outputs. For this particular relay, the input has an APC-7 connector. One side of the output has an N connector and the other side is 50 Ohm terminated. Although this relay is an RF relay, the method I described below is applicable to any latching relays.
Many dedicated ICs (such as MAX4820, MAX4821) can be used for driving such relays. Because of nature of the latching relay, no H-bridge is needed (although you can definitely use an H-bridge, but it would be wasteful).
How to drive a latching relay - [Link]
Despite a low power consumption this relay handles 5A/250VAC while maintaining a considerably long lifetime.
If we should mark an electronic component by a term “sympathic”, then the FTR-MY MY relay should be one of adepts …. Why? It´s simply chic. FTR-MY is:
- slim (5mm), so it doesn´t take much time on a PCB (only 100 mm2)
- relatively low profile (12mm), so it´s usable in majority of applications
- very sensitive (110 mW), operates even at 54 mW
- handles 5A/250VAC but thanks to bifurcated gold-plated contacts doesn´t have problems neither with small signals
- outstands by long mechanical and electrical lifetime
In praxis it looks so, that on a small PCB space, where we´d usually fit 3 common relays, it´s possible to assemble 10 pcs FTR-MY.
Despite small dimensions FTR-MY has an isolation strength of 3000VAC. Even thanks to a low power consumption, max. operating temperature is +90°C and at the same time FTR-MY enables dense assembly without worry about overheating.
The last bonus of FTR-MY is a considerably affordable price. By its specification, this series is comparable (or even better) with series NY.
Slim, humble and long-age – this is the Fujitsu FTR-MY relay - [Link]
by w2aew @ youtube.com:
Today’s “Back to Basics” tutorial topic – why flyback or snubber diodes are used around relay coils when switched or controlled by low power electronics. We’ll talk about how and why dangerously high voltages can be generated from the collapse of the stored magnetic energy in the coil when they’re switched off, and how the diode can protect the low power electronics from being damaged by these high voltages. Some voltage and current measurements are made on an actual circuit to see the real-world effects.
Why diodes are used around relay coils - [Link]
This project is an one Channel Relay Driver suitable for a variety of projects. Check specifications on the page below.
One Channel Relay Driver - [Link]
8 Channel Relay Board is a simple and convenient way to interface 8 relays for switching application in your project. Input voltage level support TTL as well as CMOS. Easy interface with Microcontrollers based projects and analog circuits.
8 Channel Relay Board - [Link]
You are planning to use Arduino in your project but you need some kind of remote control functionality. A standalone Arduino won’t provide what you need but this DIY shield may be a good solution for you. It includes a 433.92Mhz RF receiver which lets you send commands to Arduino wirelessly and four SPDT relays which can be used for switching purposes.
Each relay is capable of switching up to 10A @ 250VAC so they can be used to control mains powered devices. There are four LEDS indicating the status of the relays. The terminal blocks on the shield lets you easily connect the devices you will control.
The RF receiver is a module that can be found in the market easily. It is directly soldered to the shield and runs at 4800bps. The board has an antenna input which lets you solder your custom antenna to increase the wireless range.
DIY 433MHz RF Receiver and 4 x SPDT Relay Shield - [Link]
Remote control your electrical devices through your local network or internet. The circuit contains one output (Relay) and one input (isolated input). The whole project was built by using arduino nano platform and an ENC28J60 ethernet module. It can be used the W5100 ethernet module instead of ENC28J60, by replacing the UIPEthernet library to Ethernet library.
Moreover, the control is made from the Android application I wrote and it’s available on Google Play (https://play.google.com/store/apps/details?id=com.serasidis.NetworkRelay).
The schematic diagram, arduino sketch, photos and demonstration video is on my web site:
Arduino Network relay - [Link]
To tell the truth, probably no, but we have for you a few hints for relays which are very close to an ideal.
Signal relay is almost an „ideal component“ thanks to a practically zero distortion and a total isolation of a switched signal from a control one. That is naturally one of the main features of all electromechanical relays, but at signal relays it´s especially valued, as we usually require switching of relatively small signals. Favorite and widely used are for example relays Fujitsu series B3 and B4 (miniature SMT and THT relays) and series AxW (miniature only 5mm high relay) – all with bifurcated gold-plated contacts for a high reliability.
A novelty in our portfolio is the series Fujitsu NA representing something like a “golden middle way “. With dimensions 7,4×14,9×9,7 mm it belongs to narrow miniature relay enabling a high density of components on a PCB. Even though relay NA is somewhat bigger than for example series B4, but it´s able to withstand higher AC current – up to 0.5A/125VAC (vs. 0.3A at series B4) and it also provides an extreme mechanical lifetime up to 100×106 , what´s approximately twice that of B4 series. Sensitive coils, with a consumption of 0.1-0.3W at majority of types enable a dense mounting without problems with overheating.
From the point of view of the lowest possible consumption are naturally the best latching relays (with a permanent magnet) controlled only by pulses. Usually they´re easy to recognize by a letter „L“ behind the series marking (for example NAL, JSL). In a Fujitsu signal relays overview and the Fujitsu catalogue can be easily found a comparison among particular types as well as detailed information about them. We try to keep the most favorite types always on stock, what´s also reflected in the substantial increasing of stock.
Does a universal signal relay exist? - [Link]