TECHNICAL SUPPORT
Published 2026-03-01
Friends, I wonder if you have ever encountered this situation: you enthusiastically installed theservointo your robot or smart car, debugged the program, and as soon as the power was turned on, theservobegan to buzz and even get a little hot. You may be thinking, what on earth is this thing doing when it’s on standby? Is it also secretly consuming power? The answer is yes. Today, let’s talk aboutthe standby current of theservoand help you understand it, so that your product can have a longer battery life and a more worry-free design.
Many people think that if the steering gear is not sent a signal, it should "rest" completely and stop consuming power. In fact, this is a misunderstanding. If you imagine, there is a complex control system inside the steering gear, including a control chip, a potentiometer, and a motor drive circuit. Even if the steering gear is not turning, these "brains" and "sensory organs" are still working, ready to receive your next command. The power consumed to maintain basic operation is our protagonist today - standby current. It is like a set-top box at home. You think it is turned off, but in fact it is still consuming power silently, always ready to respond to the signal from the remote control.
This is a very real question. The standby current of the servo is not a fixed value. Its size mainly depends on the type, size and internal circuit design of the servo. Generally speaking, the standby current of common micro servos on the market, such as SG90, is usually around 5 mA to 10 mA. For some large-sized metal servos with greater torque, due to the more complex internal circuits, the power consumption of the driver chip may also be higher, and its standby current may reach 20 mA or even higher. Therefore, when you design a portable device powered by a battery, this seemingly inconspicuous standby current, multiplied by multiple servos, and then multiplied by the standby time, will become a large power consumer that cannot be ignored.
If the standby current of the servo is too large, the first and most direct impact is that the battery life will be greatly reduced. For example, if you make a battery-powered robot, it can run for an hour. However, becausethe servo's standby currentis too high, it may run out of power in half an hour, and the experience will be much worse. Secondly, the standby current will be converted into heat energy, causing the steering gear to continue to heat up. If you touch it with your hand, it may feel warm. If the system is on standby with high current for a long time and the heat dissipation is not good, it will not only accelerate the aging of the internal components of the steering gear and shorten the service life, but in occasions with relatively high requirements, it may even affect the stability of the entire system. Therefore, we must pay attention to this "silent consumer".
Do you want to personally testthe standby current of the servoin your hand? The method is actually very simple. You will need an adjustable power supply (or battery pack) and a multimeter. First, adjust the multimeter to the current setting (usually the mA setting). ️1.Disconnect the power supply: Disconnect the servo power cord (usually the red wire) from the power source. ️2.Series multimeter: Connect the red test lead of the multimeter to the positive terminal of the power supply, and the black test lead to the power cord of the servo. This is equivalent to connecting the multimeter in series to the circuit. ️3.Power-on observation: Power on the servo, but do not send any rotation signals. At this time, the value displayed on the multimeter is the standby current of the servo. You can test several servos and compare them. You will find that the differences between different brands and models are quite obvious.
Since standby current is a problem, we must find a way to solve it. The most direct and effective method is "physical power outage". In terms of circuit design, you can use a MOS tube (an electronic switch) to control the power supply of the servo. When the servo does not need to work for a long time, such as when your robot is on standby, program the MOS tube to disconnect and completely cut off the power to the servo to achieve zero standby current. When you need it to move, power it up instantly. This is like installing an independent switch for each servo. You can turn it on when you want to use it and turn it off when not in use. The power saving effect is immediate and it is a powerful tool to extend battery life.
This is a good question. If you are making a small desktop toy that is plugged in, then the standby current is really not that important, and you can pay more attention to torque and speed. But if you are making portable deviceswith product innovation and steering gear application requirements, such as wireless remote control robots, wearable devices or devices for field operations, then the standby current becomes a very critical indicator. It is directly related to the user experience and core competitiveness of the product. Therefore, when you are selecting a model, you might as well look away from the torque and speed and take a closer look at the standby current parameters in the data sheet, or ask the supplier directly. A low standby current servo allows you to have more freedom when designing power supply and battery life.
After talking so much, have you ever personally measured the standby current of your servo? Welcome to share your test results in the comment area to see which brand of servos saves the most power! If you think this article is helpful to you, don’t forget to like it and share it with more friends who make products. If you want to learn about more professional low-power steering gear solutions, you can also search the official websites of relevant companies, and you may find new discoveries.
Update Time：2026-03-01
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