Info Sheet
Quick Guide to Ignition Switches
You can use ignition switches in other applications where you need a
keyed rotary switch.
See our spreadsheet of switches, with an ignition switch for every
purpose.
What is an Ignition Switch?
Gasoline-powered vehicles need a starter system to ignite the internal
combustion engine, by means of a spark in the engine cylinder. Diesel
engines rely on fuel compression for ignition, and some have glowplugs to
preheat the combustion chamber in cold weather. We make diesel starter
switches, too.
The starter system is composed of the ignition system, plus the battery,
and starter switch, electric starter motor and solenoid. Cole Hersee
manufactures over 50 solenoids.
The basis of any ignition system is to generate an extremely high voltage
(about 20,000 volts) at precisely the right time. The voltage causes a spark
to jump across the spark plug gap, which ignites the fuel in the cylinder.
The ignition switch gives access to the ignition system.
Ignition switches usually require a key to be inserted, that engages a
lock built into the switch. It is frequently combined with the starter switch
which activates the starter motor, but if you need an ignition switch
without keys, we make those.
Since we generally initiate the motion of a vehicle commencing with the
ignition, having a keyed ignition is also a basic form of security. Heavy
vehicles may also use a master disconnect switch to completely and
safely isolate the electrical power. You guessed it. Cole Hersee makes
dozens of Master Disconnect switches, as well. In fact, when you’re
looking for switches for your commercial vehicle, you can’t do better than
Cole Hersee brand switches.
Much more on ignition systems
http://en.wikipedia.org/wiki/Ignition_system
Littelfuse Commercial Vehicle Products
PDF • 107
Switch action
•
4 position:
Accessory – Off – Ignition/Accessory – Ignition/Start
•
3 position:
Off – Ignition – Ignition/Start
or Off - Ignition/Accessory – Ignition/Start
or Accessory – Off – Ignition/Accessory
Off
Acc
Ign/Acc
Ign/Start
Or with Push-to-Choke
Off
Ign
Ign/Start
Off
Ign/Acc
Ign/Start
Off
Acc
Ign/Acc
Off
Ign
Push to Choke
Ign/Start
Littelfuse Commercial Vehicle Products • 20 Old Colony Avenue, Boston, MA USA 02127-2467
617. 268. 2100 • www.colehersee.com • www.littelfuse.com
•
2 position:
Off – Start
Or Off – Ignition/Accessory
Or Off – On (Ignition)
•
Magneto start
Off - Mag terminal to ground
Run/Acc - Mag & G terminal open,
Acc/Bat terminal closed
Off
Start
Start - Mag & Acc terminal open,
Acc/Bat terminal closed
Off - Mag terminal to ground
Run - Mag terminal open
Off
Ign/Acc
Magneto Start
Off
On (Ign)
Some lighter engines don’t use a starter motor… and don’t
carry a heavy lead-acid battery, either. Think of a lawn
mower. For these applications a magneto works fine, as
it does for gas-powered generators, chainsaws, portable
pumps, and snowmobiles. The magneto start was common
on pre-1960 motorcycles, and is still used on some small
aircraft engines, like Cessna.
Littelfuse Commercial Vehicle Products • 20 Old Colony Avenue, Boston, MA USA 02127-2467
617. 268. 2100 • www.colehersee.com • www.littelfuse.com
Keys
Not all ignition switches are keyed. We make other types, too.
95061-04 with lever actuator, no key
95062 with SAE type knob, no key
Coded or Uncoded keys?
It’s a tradeoff of security against convenience . An ignition switch with a knob has no
security. A switch with an uncoded (non-bitted) key such as the Hencol key has a better
level of security, and the coded key gives you maximum security. We offer all types.
956 series switch
with coded (bitted) key
956 series switch
with lever actuator
956 series switch
with Hencol key
Common Code or Mixed Code Keys?
We’ll sell you a bunch of ignition switches that are all operated by the same tumbler
key! Clearly it’s not as secure a system as having one vehicle/one key… but there are
lots of times when you have one vehicle/multiple operators – like a forklift truck or a golf
cart. Some fleets also operate on the one key fits all principle which saves the hassle of
maintaining a keybox, and the considerable bother of cutting multiple duplicate keys.
Littelfuse Commercial Vehicle Products • 20 Old Colony Avenue, Boston, MA USA 02127-2467
617. 268. 2100 • www.colehersee.com • www.littelfuse.com
Other features you need to know about
Anti-Restart
If you’ve ever re-started your car when it was already running, you’ll realize from the grinding noise that you can
damage the starter motor if you do. In commercial vehicles there’s likely to be ambient noise where the vehicle
operator can’t hear the engine. Anti-restart ignition switches will prevent re-starting when the engine is running. It’s an
available option in all our types of ignition switches, including the 95060 series.
Spring Return
Initiating current to the starter motor needs a momentary action only, so most ignition switches (but not all!) are
“Spring return to Off”
Key Removal
It’s useful to have they “Key removable in the Off position”, when you’re likely to leave the vehicle and take they keys
with you. You don’t want the engine running when they key is not in the ignition. That’s why most (but not all!) ignition
keys have this feature.
Sealing
Some ignition switches aren’t mounted on a dashboard in a nice dry truck cab. They’re mounted on the dash of a boat
that’s subjected to salt-spray, or for example in the open cab of a forklift truck that operates on a windswept marine
dock. The next time you start up a golf cart, just think how much that switch is exposed to the sun, wind and rain… as
well as being washed-down frequently with a hose.
We even have a school bus builder who installs
our 95060 as a security lock that’s hidden away
inside the wheel well. That’s location where you
get all kinds of dirt and splash!
95060 Ignition Switch in an exposed position on the dash of
a Stingray boat
Littelfuse Commercial Vehicle Products • 20 Old Colony Avenue, Boston, MA USA 02127-2467
617. 268. 2100 • www.colehersee.com • www.littelfuse.com
京公网安备 11010802033920号
EEWORLD
