mg995 Servo Independent Power Supply Method High Torque Servo Power Supply Scheme

The most troublesome question arises when playing withservos: Can aservowith high torque like the MG995 be directly plugged into the 5V pin of the Raspberry Pi for power supply? Presumably many friends who have just entered this field are struggling with this matter. If it is not handled well, it may directly lead to smoke damage to the equipment. Today I will explain this matter in detail at once to help you avoid unnecessary detours.

Why does theservoneed a separate power supply?

MG995 is no ordinary toy servo, its stall current can soar to 2A or even higher. The 5V output on the control board, even if it reaches the limit, is only 500mA, which cannot meet the needs of this relatively powerful servo. This situation is like using a small water pipe to supply water to a fire truck. The end result is bound to be a burst pipe.

A more troublesome situation arises. The servo will pull down the voltage at the moment of startup, causing the main control board to restart. I have noticed that many friends have fallen into doubts about their lives during the debugging process. In fact, these are all problems caused by insufficient power supply. Once the microcontroller is in an undervoltage state, the entire system will fall into chaos.

How to provide separate power supply?

The simplest way is to prepare a 6V battery pack or power adapter to provide stable power support for the servo. Connect the positive terminal of the battery pack or power adapter to the red wire of the servo, and the negative terminal to the brown wire of the servo to ensure the correct path for power transmission. The signal wire only needs to be directly connected to the control board. The three wires each perform their own duties and do not interfere with each other in the entire system, working together to ensure the normal operation of the steering gear.

️ Step one: Completely separate the servo power supply and the control board power supply

️ Step 2: To ensure a common ground, you need to connect the negative pole of the servo power supply to the GND of the control board to achieve a common ground state.

️ Step 3: There are two ways to select the servo power supply. First, you can use 4 AA batteries to power the steering gear. This method is more common and convenient, and can meet the certain power needs of the steering gear. Secondly, you can also use the 6V voltage stabilizing module, which can provide a stable 6V voltage to ensure the voltage stability of the steering gear during operation, thus ensuring the stability and accuracy of the steering gear operation.

How much current is enough?

In the no-load state, the current performance of MG995 is quite normal, about a few hundred milliamps. However, when it starts to rotate with a load on it, the current will change instantaneously and can reach about 1A. If it is blocked and unable to rotate, the current will rise sharply and can reach between 1.5A and 2A.

It is recommended to prepare at least a 3A power supply so that it is stable. Don't go for cheap and buy a copycat power supply with a nominal rating of 1A, otherwise it will stop working for you in minutes. When I used a 2A power supply to drive two servos before, the servos moved softly.

Which power supply is the easiest to use?

The 18650 lithium battery pack is indeed a very good choice. When two 18650 lithium batteries are connected in series, the output voltage can reach 7.4V. However, to adapt to some specific devices, it may be necessary to add a step-down module to reduce the voltage to 6V. Of course, it is also feasible to directly provide 6V voltage to related equipment. After all, the operating voltage range of MG995 is 4.8V to 7.2V.

If you find the operation process cumbersome and don't want to spend too much effort, then just buy a 6V 3A switching power supply, which can be easily done for a few dozen yuan. This kind of switching power supply is the most stable and reliable when used in robots, and there is no need to worry about voltage fluctuations. Never use a 9V battery because its voltage is too high and can easily burn out the servo.

Why can’t we forget the common ground?

When using separate power supply, the negative poles on both sides must be connected. This operation is called common ground. If no connection is made, the signal line cannot form a loop, and the control signal cannot be transmitted. This is like being on the phone and not getting through. No matter what you say to the servo, it can't receive the command, as if it can't hear it.

The common ground operation is very simple. Just find a DuPont wire at random and connect the negative electrode of the servo power supply to the GND of the control board. However, many people tend to ignore this key step, which leads to abnormal situations in the steering gear, such as the steering gear spinning randomly or not moving at all. The reason is actually that the signal is chaotic and erratic.

What are the consequences of unstable power supply?

When the voltage is insufficient, the most obvious manifestation is that the steering gear keeps vibrating, as if suffering from Parkinson's disease. The reason for this situation is that its internal circuit cannot operate properly and there is a problem with PWM signal recognition. If the voltage shortage is severe, the steering gear will make a hissing sound. After a long period of time, the steering gear will be scrapped.

Unstable power supply will result in insufficient power of the steering gear, and the arm that could have been easily raised is now limp and limp. When faced with this situation, do not easily suspect that the servo is faulty. It is very likely that the power supply has not been properly handled. In fact, I have encountered similar situations several times. Every time I just need to replace a power supply with good performance, the servo can resume normal operation and become lively.

You must have understood by now that the MG995 does require a separate power supply. This is not an optional situation, but an absolute necessity. What kind of power supply are you currently using to drive the servo? Have you ever encountered any problems with power supply? You are welcome to share your relevant experiences in the comment area, as a reminder to friends who have just entered this field. Please like and forward it so that more people can see it. Let’s play with the servo together and avoid pitfalls.

It is very important for novice friends to play with the steering gear and avoid detours. The experience you share may be able to help those who are new to steering gear. Whether it is successful power supply experience or power supply problems encountered, it can become a valuable reference for everyone. I hope you will actively communicate in the comment area so that more people can benefit from your experience, and together we can navigate the world of servos without being troubled by power supply problems, and enjoy the fun of playing with servos.