{"product_id":"cdu1c-fc","title":"CDU1C-FC Fast Charging Model Railway Capacitor Discharge Unit","description":"\u003cp class=\"PDq2pG_selectionAnchorContainer\"\u003eThe BLOCKsignalling CDU1C-FC is a \u003cstrong\u003efast-charging capacitor discharge unit (CDU) for model railway points motors\u003c\/strong\u003e, designed for \u003cstrong\u003esmaller layouts and straightforward point-motor installations\u003c\/strong\u003e. It provides a powerful, short-duration current pulse for reliable operation of conventional twin-solenoid point motors while helping protect the motors, switches and layout power supply.\u003cspan class=\"PDq2pG_selectionAnchor\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eThe CDU stores electrical energy in its capacitor and releases it as a \u003cstrong\u003ehigh-current pulse\u003c\/strong\u003e when a point switch is operated. This provides strong, positive movement of the point motor without requiring the layout power supply itself to provide the full switching current. \u003cspan class=\"contents\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eBecause the high-current pulse has finished before the switch contacts open, electrical arcing across the contacts is greatly reduced. If a switch is accidentally held in the operated position, the CDU limits the subsequent current through the point motor, helping protect its coils from overheating and damage.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eFast-charging CDU for model railway points motors.\u003cspan class=\"PDq2pG_selectionAnchor\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003eSingle-capacitor design ideal for smaller layouts.\u003c\/li\u003e\n\u003cli\u003eProvides a high-current pulse for strong and reliable point operation.\u003c\/li\u003e\n\u003cli\u003eHelps protect solenoid point motors from overheating and burn-out.\u003c\/li\u003e\n\u003cli\u003eReduces electrical arcing and damage to switch contacts.\u003c\/li\u003e\n\u003cli\u003eHelps prevent voltage fluctuations elsewhere on the layout.\u003c\/li\u003e\n\u003cli\u003eRecharges in a fraction of a second for rapid point operation.\u003c\/li\u003e\n\u003cli\u003eBuilt-in yellow Charging and red Ready LED indicators.\u003c\/li\u003e\n\u003cli\u003eCompatible with conventional twin-solenoid model railway point motors.\u003c\/li\u003e\n\u003cli\u003eAccepts either AC or DC power supplies.\u003cbr\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003eFast Charging\u003c\/h3\u003e\n\u003cp class=\"PDq2pG_selectionAnchorContainer\"\u003eThe CDU1C-FC uses a \u003cstrong\u003efast-charging circuit\u003c\/strong\u003e that allows the capacitor to recharge in a fraction of a second. This provides quicker recovery between point operations and can also be beneficial when using passing-contact point switches.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eLED Status Indicators\u003c\/h3\u003e\n\u003cp class=\"PDq2pG_selectionAnchorContainer\"\u003eTwo built-in LEDs provide a clear indication of the CDU's operating state:\u003cspan class=\"PDq2pG_selectionAnchor\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eYellow Charging LED:\u003c\/strong\u003e Illuminates briefly while the capacitor is charging.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRed Ready LED:\u003c\/strong\u003e Illuminates when charging is complete and the capacitor has charged to over 15V.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThese indicators make it easy to confirm that the power supply is connected correctly and that the CDU has sufficient charge available for point operation.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eWiring\u003c\/h3\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0994\/4009\/9673\/files\/Screenshot_2026-09-14_173418.jpg?v=1789403696\" alt=\"\"\u003e\u003c\/p\u003e\n\u003cp\u003eThe CDU is connected between the layout power supply and the point operating switch. The negative CDU output is generally connected to the \u003cstrong\u003ecommon connection of the point motor\u003c\/strong\u003e, with the remaining point-motor connections operated through the route switch.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eWiring Multiple Points\u003c\/h3\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0994\/4009\/9673\/files\/Screenshot_2026-09-14_173430.jpg?v=1789403696\" alt=\"\"\u003e\u003c\/p\u003e\n\u003cp class=\"PDq2pG_selectionAnchorContainer\"\u003eA single CDU1C-FC can be connected to multiple sets of points. The common wiring is simply paralleled between the switches and point motors as shown in the instructions. \u003cspan class=\"contents\"\u003e\u003c\/span\u003e\u003cspan class=\"PDq2pG_selectionAnchor\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eThe CDU1C-FC is the smallest-capacity model in the range, so if you need to operate several point motors simultaneously, one of the larger CDU models may be more appropriate.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003ePower Requirements\u003c\/h3\u003e\n\u003cul\u003e\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAC input:\u003c\/strong\u003e 12V to 24V AC.\u003cspan class=\"PDq2pG_selectionAnchor\"\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDC input:\u003c\/strong\u003e 15V to 35V DC.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRecommended power supply current:\u003c\/strong\u003e 1A.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDC input polarity:\u003c\/strong\u003e Not polarity sensitive.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTypical high-current wiring:\u003c\/strong\u003e Approximately 1.5mm² (16 AWG \/ 18 SWG) where appropriate.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eA \u003cstrong\u003e16V AC auxiliary output\u003c\/strong\u003e from a suitable model railway controller is a common power source. Suitable DC supplies can also be used, and the DC input does not need to be connected with a particular polarity. \u003cspan class=\"contents\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eFor fast-charge operation, the instructions specify a \u003cstrong\u003e1A power supply\u003c\/strong\u003e. Adequately sized wiring is also important because point motors require substantial current during operation.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003ePoint Motor Compatibility\u003c\/h3\u003e\n\u003cp class=\"PDq2pG_selectionAnchorContainer\"\u003eThe CDU1C-FC is designed for conventional \u003cstrong\u003etwin-solenoid model railway point motors\u003c\/strong\u003e operated using short electrical pulses.\u003cspan class=\"PDq2pG_selectionAnchor\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eThe instructions specifically cover \u003cstrong\u003eHornby and Peco point motors\u003c\/strong\u003e. Hornby point motors normally use the black wire as the common connection, while Peco point motors normally use green.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eWhich CDU Do I Need?\u003c\/h3\u003e\n\u003cp class=\"PDq2pG_selectionAnchorContainer\"\u003eFor compact layouts where only one or two points need to operate at the same time, the \u003cstrong\u003eCDU1C-FC Fast Charging Capacitor Discharge Unit\u003c\/strong\u003e is the most suitable choice.\u003cspan class=\"PDq2pG_selectionAnchor\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eFor larger layouts where several points may need to operate simultaneously or where point motors are further from the controller, the \u003ca href=\"https:\/\/blocksignalling.co.uk\/products\/cdu4c-fc\" title=\"CDU2CFC\" rel=\"noopener\" target=\"_blank\"\u003eCDU2C-FC Fast Charging Capacitor Discharge Unit\u003c\/a\u003e provides greater storage capacity.\u003c\/p\u003e\n\u003cp\u003eFor large layouts, demanding point-motor installations or maximum capacity for future expansion, choose the \u003ca href=\"https:\/\/blocksignalling.co.uk\/products\/cdu4c-fc\" title=\"CDU4C\" rel=\"noopener\" target=\"_blank\"\u003eCDU4C-FC Fast Charging Capacitor Discharge Unit\u003c\/a\u003e.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eDocumentation \u0026amp; Support\u003c\/h3\u003e\n\u003cp\u003eFor detailed installation instructions, wiring diagrams and troubleshooting guidance, please download the latest instruction manual:\u003c\/p\u003e\n\u003cp\u003e\u003ca rel=\"noopener\" title=\"CDU2C\" href=\"https:\/\/drive.google.com\/file\/d\/1dTz6OcwaOWfFueNjfRYOGV_-InSIuGMN\/view?usp=sharing\" target=\"_blank\"\u003eProduct Instruction Manual\u003c\/a\u003e\u003c\/p\u003e","brand":"BLOCKsignalling","offers":[{"title":"Default Title","offer_id":56860629762393,"sku":null,"price":9.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0994\/4009\/9673\/files\/cdu1c-fast-charge-capacitor-discharge-unit-1257659394.jpg?v=1788981852","url":"https:\/\/blocksignalling.co.uk\/products\/cdu1c-fc","provider":"BLOCKsignalling","version":"1.0","type":"link"}