RC car can not back down
24 Nov 2017
RC car can go forward can not back down, but to turn right normal left it why sir? That's what I'm often asked to hang out at the night market. Chat here and there finally who has a car say "yes already next week I take it for repaired" with a tone of confusion and resignation. Hehehe ... who asked electronics layman and who replied fake technicians so yes the delivery of language even make dizzy. Finally the next week the rc car was taken, unloaded on the spot, check & repair, finished.
As a form of public service (ciee ..) I have to learn to understand and repair damaged rc car unit that I rented. The impact is because often the brain even though not electro graduates so understand too. And over time by just looking at the symptoms of damage we can already guess which parts are damaged, although sometimes misdiagnosed. This is a unique mini rc car and cheap, with the same symptoms but not necessarily the same damage. And because of its uniqueness I will for discussion per case. For rc cars that can go forward but can not back down there are some diagnoses:
1. The first thing I check is the rotation of the dynamo. The way we spin the wheel forward rearward slowly, feel and hear the gearboks friction. If it turns counter-clockwise the gear feels like it involves the inside of the troubled dynamo. Usually the plates connect the current to the connector winding (if the child tamiya say it bras (brush), but not bras raskin heheh) which is broken.
2. If the wheel spin is still smooth and felt normal, we check the transistor driving. Do not confuse how to check it because it does not have a multitester tool. But if ya have gratitude for testing more accurate results. We use my way alone, unload the car body, then see the circuit engine. Notice the cable path of the rear dynamo leading to the circuit. There are four transistors. If the rd car QD four transistors are usually replaced using a relay. Turn on the car and run with the remote. Let the car do not run, under chassis wedge use something. While executed try to touch with the hands of the transistor cage, the normal condition of the transistor just feels warm (the circuit is working). But if over time it feels hot just change the heat with a new transistor. Conversely if it does not feel warm aka cold usually transistor dead. If confused replace all transistors with new ones. This I do if the heat in the change remains the same result. Yet in addition to the hot if I check with multitester still normal. So sometimes the theory with practice is not synchronized. Maybe you can ask the electronics experts why can be so, if I clear that later misunderstand it.
3. If it is checked and replaced transistors still relapse disease, we have to dismantle gearboks. Remove the dynamo from its place and then try to put the dynamo in the series of the original machine / new. If mounted in another circuit the symptoms are still the same means the dynamo is already problematic (usually the magnetic force that begins to decrease, loosely winding) the solution to replace the dynamo. There is also a way to test the dynamo is still worthy of the road or not but later in the next article yes.
Of the three ways above is usually based on my experience there is one who became the cure. Apologies if in submission there is wrong please correction from the experts, again this is only based on the experience of hobby technicians peppered with a little knowledge obtained by the writer at school. All the contents of the blog here related to electronics, although not how the value but hopefully useful.
As a form of public service (ciee ..) I have to learn to understand and repair damaged rc car unit that I rented. The impact is because often the brain even though not electro graduates so understand too. And over time by just looking at the symptoms of damage we can already guess which parts are damaged, although sometimes misdiagnosed. This is a unique mini rc car and cheap, with the same symptoms but not necessarily the same damage. And because of its uniqueness I will for discussion per case. For rc cars that can go forward but can not back down there are some diagnoses:
