Is Transistor 9013 a BJT? NPN right..?
I do not know how to connect the components for amplification, I have done all sort of ways but I still can't find an answer.

Can you guys help me with this? A schematic or something will do the job.

Basically I'm trying to control an RC(Remote Control) Car uing my laptop via USB. I constructed a USB interface circuit board which is used to connect to the laptop where the laptop also supplies the voltage of 5V(If I'm not mistaken).The battery used for the transmitter of the RC car is 9V.

What I did was when I directly connect to the transmitter from this board, the operation of F/B/L/R is only workable when the antennas of the transmitter(Controller) and receiver(Car) are at a long ruler range, not only that, the operation it is not smooth also! I guess the signal sent is too weak?

So I figured of using transistors for amplification and there's where I'm stuck at..helpppy!~!
Thnx for any replies

 

Hello,

What kind of USB interface are you using?
What is the frequency the RC control is working?
For each frequency there is an optimal antenna lenght.

Greetings,
Bertus

 

I'm using USB B-type
At the back of the transmitter, there's a sticker labelled 35MHz.

Is it that the lower the frequency consume more energy?

 

Hello,

Are you controlling something with your laptop?
How is the USB connected?

For 35 Mhz the wave lenght is 300/35 = 8.57 meter.
A 1/4 lambda antenne would be 2.14 meter.

Greetings,
Bertus

 

I'm using my laptop to control the navigation - Forward, Backward, Left and Right

I'm using an IC, 16F2550 to control the navigation (4 output)
Hence to connect with the IC, I constructed a USB interface to communicate with the IC

It's basically like this

Laptop ---> PIC (USB) ---> Transmitter

But then I think the signal is too weak or something so I put in some transistors that i thought can somehow amplify it. So it becomes like this (which is the same result)

Laptop ---> PIC (USB) ---> Transistors(breadboard) ---> Transmitter

Lol don't know whether u understand what I'm trying to deliver

According to your calculation, it doesn't fit my result. It seems to be funcionless when the range is over 20cm..........z

 

Hello,

Do you know what level is expected at the input of the transmitter?
Is this already a servo pulse signal (1 - 2 mSec pulse with pauses in between) ?
Is the PIC powered by the USB port?
The USB port of a laptop can only give 100 mA at the 5 Volts.

Greetings,
Bertus

 

it uses a 9v for the transmitter, like normally what rc car will use
Yeap i think it has
yeap the pic is powered by the port
anyway, do you know how to use the transistor 9013? which connects to which and all that? Should all the ground from each circuit be grounded?

 

Hello,

Do you have the datasheet of this 9013?
I have not found it.
Are you trying to convert the 5Volt from the PIC to 9 Volt of the transmitter?
Put a resistor of 4K7 to the Base of the transistor.
This resistor is connected to the output of the PIC.
The emmittor is tied to ground.
The collector is connected with an 2K2 resistor to the 9 Volt.
The collector has now the inverted signal at 9 volt level.

All grounds must be tied together.

Greetings,
Bertus

 

My Chinese-made solar garden lights have S9013 NPN transistors.
Wing Shing in Hong Kong make them.
They have a current gain of 64 to 202 at 50mA.
The datasheet does not have details nor any curves.

The schematic of the radio control transmitter must be seen in order to externally control it with a transistor.

 

Actually, I suppose that the 9V battery should not be implanted in the transmitter??

If i plug in the 9V battery into the transmitter, then it will solve the problem. But then, doesn't it feels like "cheating" lol

What I'm doing now is that the transmitter that is linked to my interface, is mainly "battery-less" thus no power supplied to it. It only receive power from the USB port. That's what I'm doing now~

I'm beginning to feel that this college project of mine is impossible to do............

 

The transmitter is designed to work with a 9V supply. It might not work with only 5V from USB.

You need the schematic of the transmitter in order for you to externally modulate it.

 

Hello,

As Audioguru tells you, you have to know more about the transmitter.
If the transmitter is designed for 9 Volts, use it at 9 Volts.
I have already asked you about the input level of the transmitter.
When this is known you can interface your PIC to the transmitter.

Greetings,
Bertus