User Login    
 + Register
  • Main navigation


Lost Password?

Register now!
Fast Search
Slow Search
Google Ad

[Datsun 1200 encyclopedia]

Ballast resistor

From Datsun 1200 Club

Datsun 1200 encyclopedia | Recent changes | Edit this page | Page history | Switch to MediaWiki mode

Printable version | Disclaimers | Privacy policy
Category: Engine Electrical System

The ballast resistor is used in the spark ignition system. It drops the voltage to a lower level to protect the contact points. This is sometimes referred to as a "low energy" ignition system and was the normal system through the 1970s.


A stronger spark occurs with higher voltage, so lowering the voltage -- though it protects the system -- is not a performance answer. For this reason newer Electronic Ignition systems do not use it. Early EI distributor modules (such as the 1973-1977 Datsun units) could not handle the high current and so continued to use a resistor. In 1978 they upgraded the transistor to handle more current and so were able to get rid of the resistor -- this is called a "high energy" system.

Typical specifications

22460-H7210 RESISTOR FED -0277 [for Points distributor]
* 1.17 to 1.43 ohms primary @68F/20C
23268.jpgAlbum click to view
22460-H7310 RESISTOR CAL -0277
3-tap type for early EI (low-energy and medium-energy taps)
* 1.3 ohms (.0 primary + .9 secondary) @68F/20C
24383.jpgAlbum click to view
No Resistor
* Used with high-energy ignitors and allow use of 0.7 ohm coil 

Retrieved from ""

This page has been accessed 364 times. This page was last modified 06:13, 17 April 2019. Content is available under Datsun 1200 Club.