====== IWC 7906 ======
The **7906** (and derivative **79061** and **79261**) is an [[automatic chronograph]] [[perpetual calendar]] movement produced by [[IWC]] based on the [[Valjoux 7750]] [[ebauche]] from [[1985]] through [[2016]].

===== Details =====
The [[Valjoux 7750]] movement was extremely important to the resurgence of [[IWC]] and the basic design remains in use today. The company has used it for many important innovations since the 1980's, including a [[perpetual calendar]], [[rattrapante]], and [[grande complication]]. The 7750 [[ebauche]] was used for the [[IWC 7900|790 family of movements]] and the basic architecture is the basis for today's [[IWC 69000|69000 family of movements]].

In [[1985]], IWC surprised the world with the introduction of an innovative [[perpetual calendar]] movement, **Cal. 7906**. Designed by the legendary [[Kurt Klaus]], this movement was much simpler to operate than previous perpetual calendars and was reliable and relatively affordable as well. It began with a [[Valjoux 7750]] [[ebauche]] before being disassembled and modified by IWC. The movement was refinished and plated with gold, then assembled and regulated by the company.

The original Cal. 7906 used a steel plate for the perpetual calendar module. Starting in [[1987]], IWC switched to a gold plated brass plate, renaming the movement **Cal. 79061**. Original Cal. 7906 movements were typically swapped out for this improved movement when watches were serviced by IWC. In [[1996]], IWC began using the [[Triovis]] regulating system rather than the original Valjoux Fine Regulator. This movement was named **Cal. 79261** and is also swapped during service.

The Klaus perpetual calendar movement has remained in production for decades. As recently as [[2016]] IWC has produced new [[IWC Da Vinci Perpetual Calendar]] watches with this movement. A [[minute repeater]] variant, [[IWC 79091|Cal. 79091]] was introduced in [[1991]] for the [[IWC Grande Complication 3770|Grande Complication, Ref. 3770]], and a [[rattrapante]] version, [[IWC 79251|Cal. 79251]], followed in [[1995]] for the 10th anniversary of this movement.

===== Movement Family =====
  * 7906 (1985-1988) - Steel plate
  * 79061 (1987-1996) - Brass plate
  * 79261 (1996-2016) - [[Triovis]] regulator

===== Applications =====
  * [[IWC Da Vinci Perpetual Calendar 3750]] (1985-2003)
    * [[IWC Da Vinci Perpetual Calendar 8153]] (1985-1989) - Diamond set
    * [[IWC Da Vinci Perpetual Calendar 9252]] (1985-2003) - With bracelet
    * [[IWC Da Vinci Perpetual Calendar 9253]] (1985-2001) - Diamond set with bracelet
  * [[IWC Da Vinci Ceramic Perpetual Calendar 3755]] (1986-1995)
  * [[IWC GST Perpetual Calendar 3756]] (2001-2004)
  * [[IWC Pilot's Watch Chronograph Perpetual Calendar 3757]] (2003)
  * [[IWC Da Vinci Perpetual Calendar 3758]] (2004-2006) - Larger case
  * [[IWC Da Vinci Perpetual Calendar Kurt Klaus 3762]] (2007-2016) - Tonneau case


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**Description:**
  * [[Automatic chronograph]] [[perpetual calendar]] movement based on [[Valjoux 7750]]
  * Bi-directional winding

**Functions:**
  * Hours, minutes, [[chronograph seconds]] central
  * [[Date by pointer]] at 3 00
  * [[Month by pointer]] and [[chronograph hours]] at 6 00
  * [[Year window]] at 7 30
  * [[Day by pointer]] and [[small seconds]] at 9 00
  * [[Chronograph minutes]] and [[moon phase indicator]] at 12 00

**Data:**
  * Ø 30 mm
  * 39 [[jewels]]
  * 21,600 A/h
  * [[Power reserve]] 44 hours

**Production period:**
  * [[1985]]-[[2016]]
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{{tag>Movements Valjoux_7750 Automatic_movements Automatic_chronograph_movements Perpetual_calendar_movements IWC_calibres}}