Although usually we need more RF remote control transmitters than wireless receivers, and usually we will carry transmitters around, we always see them (that’s why you will hear transmitters more often than receivers), but for something to be done, you will always need a complete RF remote control system, and the receiver is a integral part of whole RF remote control systems.
As end customer, we usually don’t care about receivers, because it is usually we already bought or integrated into a bigger control system, it is more difficult to replace, so you may or may not need this guide, but if you need to do some DIY stuff such as replace receivers, you might want to read this guide.
If you want to start new project on wireless control, for example, you need something serve as a kit to be part of your whole system,you might want to read how to choose RF remote control first to check out how to find proper transmitters part, or you can read on.
If you have already read our RF remote controls selection guide, then you will know for a logical selection, there are some decisive factors and then additional factors come into play.
We will write this article following the usual logic step, first, we will need to know what are the features of typical wireless relay receiver.
Factors of wireless relay receiver
Also we will only mention key features that are unique to wireless relay receiver, for example, One typical RF receiver is comprised of two parts, one is RF part, used to establish stable RF link with remotes, the other is processing part, used to convert button press into relay action, they’re both very important, we will describe the details is as follows.
Basic – relay factors, number & rating
For receivers part, relay number is one of the decisive factor, it describes how many channels are the receiver, is it one, two, four, eight or more?
Speaking of relay channels, customer may also need to know the rating of onboard relays, usually in V(olt) & A(mple), we will soon have a article explaining the onboard relay ratings, also you will need to know relays rating doesn’t always equal to actual rating of receiver board, because the whole circuit is relay terminal -> onboard PCB track -> screw terminal, according to the cannikin law (wooden bucket theory), the actual current rating is only as high as the weakest link, so you may expect a 10A rating on 20A relay, always contact your supplier for precise answer.
Cannkin Law – the water bucket can load depends on the lowest plate, not the highest, not the average
Basic two – power supply rating
Is it for DC or AC, low voltage like 12-24v or high voltage like 110-220v?
And you sure know what’s the power supply rating, usually if you use our receiver on your big system, you may need DC power input, because your mains board most possibly already have circuit to convert 110v ac to 12-24v dc, just plugin our common receiver would be fine, while if you prefer to use our receiver in standalone mode, sometimes you may prefer the AC input version, so you can directly wire power into our board, or you can still use our common version by employing a switching power supply or power adapter.
Many receivers’ power rating is rather limited, as it will only work at a specific voltage point, such as 12v dc or 24v dc, you will have to purchase a different version just because of voltage! it will make the stock rather complicated if you’re reseller, and will make end customer rather baffled, SKU management is very difficult too, also from technology perspective, the fixed voltage receiver version will typically have onboard linear voltage regulator, which is a old technology that is low efficiency and generates a lot of heat during working, and the AC version is likely to use capacitor to lower voltage from 110v to 12v, which is also low efficiency, and will have a higher failure rate.
While our receiver version, no matter low voltage DC input or high voltage AC input, always use latest technology switching power supply when possible, the DC version will typically have a ultra wide voltage range from 9V DC ~ 40V DC, while our most wide voltage AC version will have high efficiency AC to DC design featuring a wide voltage range from 85V AC ~ 265V AC ( please refer to our product spec. sheet for value of corresponding product, it may vary because of technology change ).
RF related – receiver module
The onboard receiver module’s performance determines actual remote distance with transmitters.
Another customer’s concern might be security and code uniqueness, you absolutely don’t want other people to open your door, and you would expect the receiver stick to the highest security standard, you will not get these in vast majority receivers on market, because they still use the old fashioned fixed code technology which can be easily duplicated, while we have long use extra secure Keeloq encryption years ago, which is pretty much a proven standard in secure garage door systems, and we have taken it even further by upgrading to 2016 NeoCode technology which uses 64-bit double security to make whole system unbreakable in most times.
For customer who wants a in-depth control of inner technical parameters, customer may want to choose working frequency, usually we would recommend 433mhz or 915mhz, the former is vastly available and have lower cost, while the later is more spectrum clear, and have less interference, meaning better RF stability, please check our choosing which remote control frequency post for more details.
In conclusion, the RF part is base of operation, it determines whether you can have a stable link between transmitters and receivers.
Advanced – working modes and programming
Working modes describes how relay react to transmitter button press, and timing control is one common feature customer asked often.
Because receiver can be as complex as possible, since it requires a lot of programming into MCU
You will also need to know if the receiver meets all your working mode requirement, working mode typically means what you want the relay to do when you press the corresponding button, it is very important as it is the fundamental feature of a wireless relay board, the most common (simple) working mode is pulse (momentary), hold (toggle), latch (which means two or more relays work in a group, one relay’s movement affects the others), our introduction to relay working modes have the modes explained in depth, please check it out if you need more details.
The vast majority receivers on market only supports the above simple mode, and most suppliers don’t support the more features because they don’t have development ability, even those who do have development ability, the working mode change usually need certain MOQ.
At Solidremote, we integrate the most demanded additional feature, the timing control, into our standard platform, so very NeoCode receiver out of factory support timing control built-in, so you will enjoy the advanced feature without any additional cost.
In conclusion, the processing part serve as core of receiver, it determines how to convert button press into relay movement.
Addon features, terminals, human interface and more
Terminals belong to IO interface, the details is as follows.
Wire terminal type, usually we will use screw terminals as they are the most widely used terminal type in receiver line, and it offers flexiblity to connect to many existing wire systems easily, also the screw terminal can withhold high current ratings.
While screw terminal offers so much flexibility, it also has downsides, for example, you will need to use screwdriver (tools needed), and you will need to fix every terminal (if you have total 6 wires to connect, you will need to perform same step 6 times), so it’s not very easy to use.
So for customized projects, we can work with customer to provide some plug-and-play connector, the most widely used ones being XH2.54 terminal, RJ11 terminal and RJ45 terminal, you can take advantage of the widely used connector type in industry, to save cost and maximize compatibility.
Sometimes our enclosure is waterproof, meaning you will need to use screwdrivers to open case to touch inner board, sometimes it is not very easy, since a simple programming will need you to use tools, and take some time, we have our special solution to use magnet to ‘touch’ inner program button contactlessly, thus will greatly shorten the program time, making programming a breeze.
The other terminal we may have is the limit switch terminal, which will control the relay movement by sensing third-party signal input, such as limit switch signal.
DIP switches also makes the extra functions switch very easy.
The last, but not least, a very important IO for wireless receiver is the antenna terminal, while most systems still use soldering to solder the antenna wire directly to board, it is of course very cost effective, but it is not very easy for customer to switch for longer range antenna, customer will need to have soldering tools and skills, which will render antenna switching impossible in most circumstances.
We also use the old soldering technique in older systems, but in our latest 2016 range, we decided to switch to industry standard IPX port onboard, for easy antenna switching, every customer is possible to switch antenna very easily.
Also, from a technology perspective, the older technique usually doesn’t solder ground wire, which means the conduit not as efficient as it is designed to be, while our new IPX port will keep up to industry standard, enabling maximum performance in tiny package.
For more information regarding external antennas, please check out our antenna design guide blog series.
And still there is a very important part, the actual design of receiver.
Receiver design, whether from outside or from inside, is very important, and can be considered the soul of receiver, a good design can make user very happy in use, while a bad design will actually try make customer very frustrated.
Here at Solidremote, our design principle is to make receiver (and all of our products) as human friendly as possible, the primary and only goal of our design is to make user happy, so we are the one of the first to use DIP switches on common purpose receiver (instead of old school jumper), and we are also one of the first to use digital display on universal receiver (to display numbers, instead to let customer guess by flashing LEDs), we will continue to use cutting edge design on our NeoCode receivers and beyond.
How to choose wireless relay receiver
Same as with RF remote control choosing, we will divide into two parts, first is for a brand new system, the second is for compatibility with existing transmitters part.
Part one, for a brand new system.
This is from customer requirement, customer care perspective, for brand new system, you will probably consider the factors in steps below.
1. How many channels do you need
for example, if you only need to control one circuit on and off ( as we see in most circumstances, for example, in your door receivers, the external receiver is only 1 channel, it only needs to connect to your garage door’s manual button input, and in your lighting control systems, you will only need to switch light on and off ) then you might want to look for 1 channel receivers, while if you need to control more gadgets (for example, you may need to control DC motor forward and reverse) you will need at least two channel receivers, and you might need more channel receivers if you need more control.
2. The relay rating you need
It depends on the target you need to control, control a single button obviously isn’t the same as control a large pump motor, the former only need mA current, while later may need several A.
3. The power input rating you need
Start with something you prefer, for example you would prefer something accept 110vac power if you’re to plug it into the mains supply, or you can always use a external power adapter to use our standard 12-24vdc wireless relay receivers.
4. The distance you need
This need to be considered together with choosing RF remote controls, as they always work in a pair, different receiver modules used by different suppliers can cause significantly different distance is real field test, we always use best receiver modules possible in the class.
5. Working modes & other factors
The other key component is working mode, you have to make sure the product has working mode you need, so you can use it to achieve what you want, also you may consider other points, a easy to use receiver will save you a lot of time no matter if you’re end customer or reseller.
Part two, for existing RF compatibility
There are some circumstances that this type of change is necessary, for example, your exising RF receiver is broken, you may need to change, so you will look for compatible receiver, right now, our compatible receiver line is limited, we only have one type compatible that is 433 OOK Keeloq. (433 means frequency, OOK means the technology, while Keeloq means something by Microchip, which is popular in garage door control systems).
Unlike looking for compatible remotes, our receiver line for ‘compatibility’ is rather limited, as we only provide universal receiver for several circumstances, the key points is as follows.
1. Your remote is using 315MHz, 433.92MHz or (sometimes 868.3MHz) frequency.
2. Your remote is using OOK ( not FSK ).
3. Your remote’s chip must be one from the Keeloq series, either HCS200, HCS201, HCS300 or HCS301.
For above check, you may want to check our post on RF remote controls for existing RF compatibilty check, such as frequency, OOK or FSK, encoder format etc.
If your remote matches above requirement, which we call 433 OOK Keeloq systems, we can use many existing garage door remotes, such as those used in European countries, or Australia, if your system is other than this, we would recommend you contact your supplier or upgrade both remotes & receiver to new kit, refer to part one, which gave many advantages at same price.
And due to the complexity of receivers, our receiver, if used as replacement purpose, is recommended to only replace the smallest part possible, which means only the key RF part used to convert button press to simple circuit on and off, then leave the post processing step to original logic or main processor.
(To be continued…)