Last Updated on March 16, 2024
Charging Electronic Devices Wirelessly becomes Normal now a days, Why we charging mobile phones only. Lets charge every electronic device wirelessly. Here Wireless Charger Circuit NiMH Battery designed to charge 25mA tiny NiMH Battery by using two standalone ICs LTC6990 and LTC4123. This circuit with PCB mentioned here is a Test Circuit and suitable for Experiment only and not for real applications. Here Charging transmitter and Receiver coils are mentioned as Inductors, Use proper transmitter and Receiver Coils.
IC LTC6990 from analog is a precision silicon oscillator with a Programmable frequency range of 488Hz to 2MHz. It can be used as a fixed frequency oscillator or voltage controlled oscillator. Here a single Resistor Rset programs the LTC6990s internal master oscillator frequency. Refer datasheet for more information.
Wireless Charger Transmitter Circuit Diagram
Components Required (BOM)
| 1 | C1 | 4.7µF | C_0805_2012Metric | 1 | ||
| 2 | C2 | 100µF | C_0805_2012Metric | 1 | ||
| 3 | R1 | 205K | R_0805_2012Metric | 1 | ||
| 4 | U1 | LTC6990HDCBTRPBF | DFN-6-1EP_3x3mm_P0.95mm_EP1.7×2.6mm | 1 | ||
| 5 | CTX1 | 33nF | C_0805_2012Metric | 1 | ||
| 6 | CTX2 | 1nF | C_0805_2012Metric | 1 | ||
| 7 | LTX1 | 7.5µH | L_Axial_L7.0mm_D3.3mm_P12.70mm_Horizontal_Fastron_MICC | 1 | ||
| 8 | Q1 | Si2312CDS | SOT-23 | 1 | ||
| 9 | J1 | Screw_Terminal_01x02 | JWT_A3963_1x02_P3.96mm_Vertical | 1 |
Printed Circuit Board (PCB)
Wireless Charger Transmitter Circuit PCB Gerber files.
Interactive Board Viewer
Wireless Charger Receiver Circuit Diagram
Components Required (BOM)
| 1 | D1 | LED | LED_0805_2012Metric | 1 | ||
| 2 | U1 | LTC4123 | DFN-6-1EP_2x2mm_P0.65mm_EP1x1.6mm | 1 | ||
| 3 | CIN1 | 4.7µF | C_0805_2012Metric | 1 | ||
| 4 | CRX1 | 33nF | C_0805_2012Metric | 1 | ||
| 5 | LRX1 | 13µH | L_Wuerth_WE-PD-Typ-LS_Handsoldering | 1 | ||
| 6 | RPROG1 | 953Ω | R_0805_2012Metric | 1 | ||
| 7 | J1 | Screw_Terminal_01x02 | JWT_A3963_1x02_P3.96mm_Vertical | 1 |
Printed Circuit Board (PCB)
Wireless Charger Receiver Circuit PCB Gerber Files.
Construction & Working
IC LTC4123 from analog is a low power Wireless Receiver and constant current / Constant Voltage linear charger for NiMH batteries. An external programming Resistor sets the charge current up to 25mA.
The LTC4123 is a low power battery charger designed to wirelessly charge single cell NiMH batteries. Magnetic field to the Receiver coil induce EMF and this Rectified by the internal Rectification and input power control block. Another logic control block decides the charging current output. Constant current and constant voltage block Regulates the supply and allows to BAT pin. This IC comes in a tiny package and hence suitable for tiny device designs. Refer datasheet for more information.