This is the second post of our ‘the road to better receiver’ series, in the previous chapter, we have focused on how to design better receiver’s key component, the receiver module, while receiver module is important, it is not the only important component on receiver, in this chapter, we will focus on another basic part, which is the power supply circuit.
When we design the power circuit, our goal is simple, the first goal is, we need to make the receiver as ‘universal’ as possible, the second goal is, we need to make the receiver as green as possible.
Universal voltage as our goal
For the first goal, universal means our receiver can work under a wide range of voltage ratings, from lower voltage such as 9V to upper voltage such as 30V, they are all commonly seen on market, for example, some older garage door openers will output 24vac voltage, while other newer ones will output 12vdc voltage.
In existing solutions on market, we will have to use different receiver for different voltage, which is just not right, for example, you as end customer, bought a 12vdc receiver only to find your power input is 24vdc, it will be very frustating to have to send the receiver back or throw it away, if you’re a reseller, you will have to stock different receivers just have different voltage rating for your customers, and you don’t know which receiver sells the best, so there will always be dead stock in your hand, which is not so good.
So we have designed our receiver to use the switching power supply, found on newer electronic devices such as computers, mobile phones and etc, the switching power supply has enabled us to use a wide range of input voltage.
Green receiver is also important
Also we need to make our receiver as green as possible, although most receivers draw power from mains supply, you don’t have to worry too much about power consumption, and most receivers on market only have power supply in matter of milliampere, just a small number, a 1/1000 of one ampere, but don’t forget most receivers will be always on, a quick calculation will give you 105.12Wh power consumption per year if only the difference is 1mA! (number is rectified thanks to Tadej Koncan).
Luckly, the switching power supply we used also enabled us to make the receiver as green as possible, switching power supply is much more power efficient compared to traditional options such as linear power regulator, especially at higher voltage, so our receiver can keep as low as 8mA standby current at 12v, and even lower current at 24v.
Special power supply is also possible
We also have special solutions for some customers, for example, one customer would need our receiver to work under 6v voltage, which is not possible in most receivers on market, because most receivers on market will use relay rating at 5v, and it will require a very small voltage drop on power regulating circuit. Our engineer has tried many solutions and found one which meets the goal, the low dropout LDO we used can meet the customer’s requirement while ensures the stability.
Evolving power supply
Even our existing our supply is already one of the best on market, our engineer is always looking for a even better one, because we know in the fast changing world like this, our technology need to be runing fast to keep up the pace, during our whole receiver line, we have the following generation.
Generation 1, the old linear power supply, it is used on all our receivers pre-2011, it will usually use Holtek chip or 78xx series regulator to work, and it is just like most products on market now, will need to have version difference, such as 12v, 24v etc, each version needs to have one receiver.
Generation 2, the linear power supply+ version, it will also use linear power supply, but will use 2 regulators on board, and jumper to choose which regulator to use, so it can work with 12v or 24vdc, but users will need to choose power voltage properly, or it might damage the receiver itself, also it may not support power between the two voltages.
Generation 3, the switching power supply version, uses the old generation switching power supply, support voltage up to 35v dc, and the size is somewhat bigger due to requirement of larger inductor and footprint.
Generation 4, the switching power supply+ version, we will use newer generation chip which support up to 40vdc, the footprint is much smaller, and surrounding component will use surface mount versions to be better performance and stability.
Also our engineer is studying newer generation power circuit to make it better and better.
(To be continued…)