Inductive telemetry is the only technique available nowadays for powering an electronic or microelectronic device placed in a far or unreachable location that needs an external power supply. The presented system is used when an electronic device needs to be powered continuously and, also it can be useful in those devices powered by a battery when it is exhausted. Furthermore, in general terms, this inductive link can also send information to steer and control any internal or implanted device. Patent application sectors are: robotics, prosthesis, electro-medicine, machinery fabrication industries, security services and some others.
This presented inductive link consists of two elements:
1. An external transmitter responsible for energy and data transmission. It is based on a Class-E amplifier and it uses a new schema to implement modulation allowing a high bit rate in data transmission and controllable power consumption.
• Class-E energy driver with a resonant L-C (Load Cell) load the values whereof are fixed by the carrier frequency used
• OOK (on-off keying) data modulator, modifying the resonance frequency or the transfer function in the class-E amplifier
• It controls transmitted power
2. An internal receiver applies a resonant tank joint with a rectifier to transform the received ac energy in a constant power to supply the internal device or recharge the battery. Besides, a single demodulator gets data to be used in the receiver to control or steer a particular device. This new configuration allows to optimise the energy reception and to make the modulation index load-independent, thus reducing the number of dissipative components in the device to a single diode in the rectifier. Consequently, higher efficiency in power transmission is obtained with this configuration.
The most significant innovation is the development of a telemetric link based on inductive coupling for power and data transmission with enhanced efficiency and higher bit.
Another innovation is related to the serial connection of the resonant tank and load in the receiver and the strategy used in the OOK modulation in the transmitter.
1. The transceiver presents a high efficiency (around 50% at 2 cm) in power transmission.
2. The modulator depends only on the amplifier transfer function, thus a high bit rate (1 Mbps) in data transmission is obtained.
3. The transmitter power consumption can be controlled and modified according to the receiver requirements.
4. The L-C serial connection with the load in the receiver makes constant the resonance frequency, making the undesirable adjustment of the carrier in the transmitter redundant.
5. The modulation index in the receiver is kept load-independent.