CGo3 Gimbal Board Chip

[WTFDproject]

Does anyone know how to identify this chip, or where I might find some? I tried searching using the markings on the chip, and it leads me to a different component. There are two of these things on the gimbal board of a CGo3 camera, and I suspect they are involved with an issue with the gimbal.

 

[DoomMeister]

This might be the answer for the first post.

TL3843D-8 Texas Instruments | Integrated Circuits (ICs) | DigiKey

Order today, ships today. TL3843D-8 – Boost, Flyback, Forward Regulator Positive Output Step-Up, Step-Up/Step-Down - DC-DC Controller IC 8-SOIC from Texas Instruments. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

The Datasheet link is at the top and shows that it is a PWM controller.

 

[SmittyInTheSky]

Try MCP8063. This may not be bidirectional though. I think the 3 wire connectors suggest the gimbal motors are 3 phase. We need to find a bidirectional BLDC for brushless motors in a 4x4 DFN package that fits the electrical specs of the main board psu.

 

[SmittyInTheSky]

I believe the mechanism being used to control the gimbal motors with the magnet is called sensorless field oriented control (FOC). It's commonly used with BLDC (BrushLess DC motor)

 

[SmittyInTheSky]

I may be overthinking this. Maybe no bidirectional feature needed since gravity is doing a part too. Speed up/slow down motor signal results in gimbal axis tilt due to gravity and trimmed by bldc. I bet MCP8063 will work.

 

[WTFDproject]

I may be overthinking this. Maybe no bidirectional feature needed since gravity is doing a part too. Speed up/slow down motor signal results in gimbal axis tilt due to gravity and trimmed by bldc. I bet MCP8063 will work.

When the camera is properly set up in balance, wire (twist) tension and frame alignment there is no net gravity effect on either the pitch axis or the roll axis. The limited Yaw movement of CGo3 is not affected by gravity at all. Also, these motors don't spin (Speed up/slow down). They are positional motors that just go straight to the angle dictated by the gimbal board and stay there until the signal changes.
I don't know much about the electronics you are discussing. All I can offer are these small clarifications in hopes it will help a little.

 

[SmittyInTheSky]

Here's a good introduction to how the system works.

3 phase motors work a little differently from regular DC. I'm still trying to figure out some things too.

3 wires to motor energized with 3 phase AC(yes?)
Magnet on drive shaft
As5600 senses magnetic field orientation and encodes drive shaft position in pwm. As5600 uses three wires, Vcc, gnd, and pwm.

 

[SmittyInTheSky]

The motors do vibrate when they're energized. I think that's the 3 phase being modulated to keep the drive shaft position oriented in one place. That's why there's the little rubber dampener on the back of the cgo2.

Another good video on principals.

 

[SmittyInTheSky]

I'm getting ahead of myself, I need to verify function of the original chip. Apologies.

 

[h-elsner]

According the Configuration Register of the AS5600 the output is "Analog (reduced range from 10% to 90% between GND and VDD). But no matter if PWM or Analog, the control loop is angle actual <> angle target -> motor corrects angle. Modern gimbals use brushless motors because they have a high torque even at the lowest speed or angle.

The IC above is not for motor control. The motor driver are on the other side of the PCB. There 5 pieces of DRV8839. The have together 10 outputs for coils, 9 are used (3x3) for the 3 motors.

What the two AJDF chips are for I don't know. I can imagine that this are MOSFets for switching power supply 5V or something like that.
Another idea: A TC1301. See: The SMD components marking codes database - Starting with 'AJ'
At least the ground pin is at right place for TC1301.

br HE

 

[SmittyInTheSky]

According the Configuration Register of the AS5600 the output is "Analog (reduced range from 10% to 90% between GND and VDD). But no matter if PWM or Analog, the control loop is angle actual <> angle target -> motor corrects angle. Modern gimbals use brushless motors because they have a high torque even at the lowest speed or angle.

The IC above is not for motor control. The motor driver are on the other side of the PCB. There 5 pieces of DRV8839. The have together 10 outputs for coils, 9 are used (3x3) for the 3 motors.

What the two AJDF chips are for I don't know. I can imagine that this are MOSFets for switching power supply 5V or something like that.
Another idea: A TC1301. See: The SMD components marking codes database - Starting with 'AJ'
At least the ground pin is at right place for TC1301.

br HE

I'm wanting to sit down and try to pin-out the AJDF chips. Ideally we could get someone to hook an o-scope up to the pads once the chip is removed to see what input looks like. My scope is broken for the foreseeable future, unfortunately.