Salter Pepper mill: Upgrade for larger capacity & Li-Ion power + Charger

prusaprinters

Increases input voltage from 6 to 8.4 V thus increasing power. More than doubles pepper capacity.Additional components needed: - 1 Salter automatic pepper mill: Needs to be disassembled and the lower part with the mill and the container and the Motor assembly without the batterie pack are reused. - 2 LFP cells (lithium iron phosphate): 65*18.4 i.e. HAKADI 3.7 V 2000 mAh / 7.4 WH - Charging electronics, i.e. FDC-25-2 - DC-DC step up converter, i.e. XL6009 DC-DC Boost Converter Modul - Mico-USB connector - 3 position switch (left, right, idle) - cables - Set head Screws M3*40; M3*30; M3*20 - Components to solder PCBA acc. to attached scematicsAll threads need to be cut using a M3 thread cutter (2.5 mm holes are prepared.In order to charge the “Button” needs to be tilted forward which openes the charge door that protects the micro-USB from kitchen grease vapour. This triggers the LED which is permanently active reminding the user to close the cover by moving the “Button” into the middle position to separates the DC-DC converter from the LFP batteries. The switch as acted upon by the “Button” needs to be configured accordingly.Cable management may need some work. Holes for cables underneath button may need to be enlarged. Micro USB cable that has fitting connector for hole in housing needs to be selected.If no Charge indication LED is used the LED_Glas_Body may be printed from a non transparent material. This is not adviced as the charging door may be left open leading to grease in the micro USB connector.Shunt resistor (resistance value not on scematic) on PCBA should be 0.5 to 1 Ohm and should have high power rating (just use 2 one Ohm resistors in paralell). The potentiometer should be adjusted so that the blue LED is illuminated if no current is flowing and the red LED is illuminated if current is flowing. A 1000 µF capacitor, charged through a diode, may be used to separate the powersupply of the NE555 from the DC line to stabilise the powersupply and keep the LED on if the USB charger does not have sufficient power to keep up the voltage during charging (however this may not be nescessary).I refuse to elaborate why this exists.