RC Car Toy Modification Help !!!

[battery.13v]

Hello everyone !!!
i have this 2 RC car toys in the junk ... so i have the idea to modify them into one car that has much power and speed .... So i reassemble them into one frame and i got this one :

This new Toy contain 2 DC motors in the Rear and One Steering Dc Motors in the front ...

the old circuits contain just 2 H-bridge for 2 Dc motors, when i test it one H-Bridge is Burned out cause i connect it to 2 Rear Dc Motors,
So i figured out that i have to add a new H-Bridge to my second rear Dc Motor ...
The demodulator is a chinese clone of the RX-2 Chip ...
When i tested it's output i found that it output pulses (when i trigger forward it generate a positive pulse ...
and when i release the forward trigger, it generate a negative pulse ) and with this pulses it make the DC Motors Runs ....
So i searched in the Internet and i figured out that it could be a latching circuit after this pulses ...
However when i retrace the Circuit i did not found any LAtching Circuit ...
So this is my problem and i want someone to tell me how this thing "Chinese RX-2 Chip" control the DC motors with Pulses ?????







You will Found in the attachement the circuit schematic of the H-Bridge




Here is a video about the result of the oscilloscope in the output of the left and right ouptut pin signal

https://sendvid.com/hguz65wg

So i want to know how this thing make a dc motor turn on ??
How could i make another H-Bridge that trigger on with this kind of pulse for my Third DC Motor ??

Thx ??

 

[Audioguru]

You have made this thread on at least 2 other forums. Your video did not work on those forums but it works here.
The datasheet for the receiver IC says that it latches an output when it receives the coded pulses and its MOD pin is high. The output pulses when it receives the coded pulses and its MOD pin is low.

 

[ahsan_i_h]

Probably you have selected AC coupling in function menu on the oscilloscope. When AC coupling is selected, the oscilloscope uses a capacitor to block DC and pass AC. The positive/negative pulse is appearing due to charging/discharging of that capacitor. Set DC coupling in function menu. See the picture below.

 

[Audioguru]

The motor in the video sounds like it is pulsing on and off over and over. Instead it should be driven with steady DC.
The datasheet for one receiver IC shows that its MOD pin causes or stops pulsing.

 

[battery.13v]

Probably you have selected AC coupling in function menu on the oscilloscope. When AC coupling is selected, the oscilloscope uses a capacitor to block DC and pass AC. The positive/negative pulse is appearing due to charging/discharging of that capacitor. Set DC coupling in function menu. See the picture below.

Thx Mr ahsan_i_h the problem was from the oscilloscope like you said it was in the AC coupling Mode ... and when i changed it it worked perfectly

- - - Updated - - -

The motor in the video sounds like it is pulsing on and off over and over. Instead it should be driven with steady DC.
The datasheet for one receiver IC shows that its MOD pin causes or stops pulsing.

I want to thank for you reply ... the problem was from the oscilloscope ...