GoolRC HJ Digital Servo Tester/ESC Consistency Tester for RC Helicopter Airplane Car

This is a nice little inexpensive servo tester that works well. The control knob seems pretty linear and the unit puts out pulses between 800 usec and 2200 usec. There is no manual for it, which is annoying, but the pinout couldn't be simpler. There are five sets of three pins ... the three pins are arranged vertically and the sets are arranged horizontally. ALL of the pins that are toward the back of the unit are negative ground ... they are all common, there is no difference between them. ALL of the pins in the middle row are positive voltage ... nominally 5 volts. They are all common to each other ... you can provide the required five volts to any one of them and send 5 volts to power the servo from any of the other pins in that middle row. The pins in the upper row are ALL for the 5 volt pulses that get sent to control the servo. I don't think it matters which of of them you use either. I've bought four of these units ... they all worked the same, and they all worked fine. I actually used two of these servo testers to control a couple of very strong 150 kg-cm 12 volt servos. I provided 5 volts to power the servo testers, and separately provided 12 volts for the servos themselves. The 5 volt signal pulses from the servo tester controlled the servos just fine, and the only requirement was to make sure the ground for the servo testers and the ground from the 12 volt supply for the servos were connected.

I needed something that would do analog servos as well as digital and this fit the bill perfectly. I made my own 4xAA holder to power it using a cord off a deceased cheap servo. The controls are easy once you figure them out but an instruction sheet would have been handy. There is a manual testing mode, a centering mode, and a sweep mode. In sweep mode the knob controls the speed of the sweep. You can choose 50,125,or 250Hz before plugging in your servo. I tested some known bad servos and was able to see the problem on each. One oscillated in the model it was in and one would stick at times. The tester verified the problems in these.

This servo tester works as promised. I can test 4 servos at the same time. This is my first time working with servos by the way. Cons: * Lack of manual. For beginners it's intimidating to determine which pins are positive and negative. * Lack of Amazon review photos. I wonder why no one has bothered sharing any, so I am sharing some. I hope it will help Pros: * Works with 4 servos * Digital display Suggestions for improvements: * Step by step visual guide * Better markings on the unit * Metal or sturdier build would be nice Tips: * Check my screenshots and video! * First row from the top is where the positive and negative pins are * The negative pin is the one closer to the floor * The positive pin is the next pin after the negative pin. This is the middle pin. * On your servos, the brown wire is the negative * Use an external power supply if you are powering 4 servos. I used a Raspberry to power up 4 servos but it wasn't able to supply enough voltage. An AC adapter made it work seamlessly Units I used on these photos: * HJ Servo Tester (obviously) * Longruner SG90 Micro Servo 9G * JBtEK breadboard power supply * Zozo 3v-12v regulated multi voltage AC adapter

Garbage, did not work from day one! ...at lest it's only the cost of a couple beers I blew on this thing :)

Works well. It's nice to be able to automatically dial in 1500 or to also sweep the spectrum with hands off. Useful tool to also test engine efficiency. Only criticism would be that it would be nice to have the +- indicators more intuitively laid out on the device (like on the side).

Must have for airplane servo set up. Manual, auto and center finder digital and analog

Simple and effective. Yes, you do have to supply your own battery to power the unit, but that should not be an issue. If it is, you are in the wrong hobby. I did run into a minor issue when I tried to use a battery that was near the end of it useful charge and the readings the unit was giving were way out of wack, but after plugging in a fully charged battery, the unit responded perfectly. As with any product, how long the unit preforms well will be the key factor.

It worked fine initially tho the POT is hard to adjust precisely to a specific PPM value.. However mine died on the second use.. The thing that confused me was seeing the Horizontal Labels on the edge of the case .. I was plugging in horizontally .. Yet the actual Pin orientation needed is Vertical .. with Black/Brown on the Bottom pin and the Signal on the Top Pin as viewed from the side.. Anyway I did not expect ANY mis-pinning could damage it.. My other old servo tester is bullet proof in this respect.. But mine smoked some component inside ( I can smell it) .. and Amazon offered to replace it so it's in the mail on the way back and I will be more cautious when plugging in the battery to the new replacement..

Excellent piece of kit comes packed on a card and the product itself seems excellent quality and well featured ,the digits are clear and bright and plenty big enough ,a freind of mine tested the acuracy on his ocsiloscope and its EXTREMLLY ACURATE and for the price literaly pennies its a bargain i used it intitialy to center my servos but also use it primarilly NOW AS A VERY ACURATE AND USEFULL PIECE OF KIT TO TEST BRUSHLESS MOTORS ,AND EVEN CALIBRATE ESC,S WICH I DIDNT EVEN KNOW IT WAS CAPABLE OF DOING but it does and with ease and accuracy

A simple 3 mode servo tester, but with a digital read out, allowing you for example to set the middle point accurately.

説明書がないので、電源のつなぎ方が分からず、試行錯誤したので参考のために書きます。入力端子に向かって一番左側から電源を入れます。一番上の端子は使いません。真ん中が電源(プラス)、一番下がGND(マイナス)。残りの4セットの端子はサーボを繋ぎます。パネルにある2つのボタンの使い方です。左のセレクトボタンを1回押すと、サーボの移動の中間地点になります。もう一度押すと自動で最小と最大を繰り返します。電源は入れた時は手動モードになります。右側のパルスボタンですが、押すたびに周波数が変わります。これはデジタルサーボ向けです。普通のアナログサーバーでは使いません

Tests and centres servos. Good build quality, not great. 3 stars because of the lack of instructions.