• us-602
  • us-622
  • us-625
  • us-630
  • us-638
  • us-802
  • us-828

News & New Product 新着情報 ( ニュース と 新製品 )

2020.06  IATF16949 registration certificate was renewed after receiving a pass judgment in the regular examination.
2020.03  New US-638 with high-capacity contact material for automobiles that uses DC48V and MAX3A has been released.
2019.01  We announced the launch of the small thermostat US-639.
2017.08  ISO / TS 16949 new registration was officially decided, and a ceremony ceremony was held on 30th August. More
2017.05  On May 18th, Chinese factory was certified as a high-tech enterprise in Dalian City and an official certificate arrived. More
2013.08  Capital investment business in the Company’s new products, was adopted as the subject of the Ministry of Economy, More
2013.02  We renewed the new (Japanese) Asahi Keiki Co., Ltd. home page. More
2011.07  From everyone of many, we receive the inquiry in regard to the Fukushima plant the Great East Japan Earthquake More
2011.04  I would respectfully sympathy to everyone that has been affected by the Great East Japan Earthquake More
New US-639  ultra compact(3.8mm)with lead wire, flat type thermostat PDF catalog
639 Features Heat Resistant Resin Body -Water Resistance by Resin Filling 6392
Application Handle heater, water heater, vending machine, more etc.
New US-638  ultra compact & water-proof thermostat   PDF catalog
63801a Features Resin seal structure in the ultra-thin 63803a
Application Fuel cells, medical devices, surveillance cameras, car seat etc.
New US-828  compact design, S.O.D. specification compliant thermostat   PDF catalog
828AXAB04 Features Insulation-enhanced compact design, S.O.D. specification compliant model 828AXBB02
Application Office automation equipment such as copier, printer, laser MFP, etc.
New US-628  Drip-proof, compact design thermostat PDF catalog
628AXSSAS-F Features Drip-proof, compact design, general purpose, low cost 628AXSSFF-F02
Application Suitable for wide range of applications such as gas and oil appliances, fuel cell, etc.
US-802  Microminiature, slim, space-saving thermostat for P.C.B. PDF catalog
80202 Features Microminiature, slim, space-saving thermostat (with temperature sensor) ideal for printed circuit boards (PCB) 80201
Application LCDprojector, power supply equipment, printed circuit board (PCB), etc.

Select by Model製品タイプからの サーモスタット選定

General Type


Small sized (1/2 inch) and high capacity

High Temperature Type


Small sized (1/2 inch) and high capacity

Manual Reset Type


Small sized (1/2 inch) and high capacity

One Shot Type


Small sized (1/2 inch) and high capacity

Water-proof Type


Small sized (1/2 inch),high capacity
Drip-proof, compact design, general purpose

Thin Type


Case attachment type, Heavy case type, with / without thermal fuse

Compact Type


Microminiature, slim,for printed circuit boards

Variable temperature




SInsulation-enhanced compact design, S.O.D. specification compliant

Select by Application 製品用途別からの サーモスタット選定

Household Equipments

Ovens・Hot water kettles・Coffee makers・Washing machine・Vacuum cleaners・Refrigerators

Gas Equipment

Fan heater ・Water heater・Gas boiler・Built-in stove

Residential Equipments

Floor heating system・Electric mats・Electric water heater・Lavatory seat

Commercial Equipment

Automatic vending machine・LCD projector・
Rear projector TV

Office Equipments

Copy・Printer・Laser MRF・Office automation equipment


Car steering wheel heater・Car seat・Electric cart・Outboard motor


Alkali ion water purifie・Power supply・P.C.B.・Construction tool


Thermostat selection from the list一覧表からの サーモスタット選定

Appearance Model Size(W×D×H) Structure Contact AC125V Rating Temp. range diff Application
US-118 118 16φ×20 Fully enclosed stainless case φ3 Silver or Gold crossbar 3A DC 24V 1A 0~250℃ 15~30K Motor・transformer・water heater・automobile engine・watercraft
US-415 415 25×67×43.5 Laminated structure、Temp. variable φ4.5 5A(Lamp) L:AC125V 6A(Lamp) 70~105℃ 7~15K Kotatsu anchor
US-602 602 Body φ16×9.3 Phenol resin case φ3 Silver or Gold crossbar 15A AC250V 7A 0~150℃ 12~20K Microwave oven・motor・burner・Prevent overheating of office machines
US-603 603 Body φ16×15 Manual reset type・Phenol resin case φ3 Silver or Gold crossbar 15A AC250V 10A 50~150℃ Microwave oven・motor・burner・Prevent overheating of office machines
US-621 621 Body φ15.8×11.8 PPS resin case φ3 Silver 15A AC250V 10A 0~200℃ 12~30K/td> Copying machine、LBP
US-622 622 Body φ15.8×12.4 Polyester resin case φ3 Silver or Gold crossbar 15A AC250V 10A 0~185℃ 12~25K Microwave・heating equipment・water heater・business machine
Appearance Model Size(W×D×H) Structure Contact AC125V Rating Temp. range diff Application
US-623 623 Body φ15.8×12.4 PPS resin case、Manual reset type φ3 silver 16A AC250V 16A 50~200℃ heating equipment・water heater・Vending machine
US-625 625 Body φ15.8×12.4 Ceramic case φ3 Silver or Gold crossbar 15A AC250V 10A 100~250℃ 120~30K Microwave・heating equipment・water heater・business machine
US-628 628 Body φ15.8×12.4 Phenol resin case φ3 Silver 10A AC250V 5A 0~130℃ 12~20K Water heater・antifreeze
US-630 630 Body 22.2×33.7×6 PBT insert φ2.5 Silver 8A AC250V 4A 0~120℃ 10~12K Electric mat・floor heating・water heater・Vending Machine
US-802 802 Body 10.8×29.5×4.5 PBT Insert φ1.6 Silver 1A DC48V 1A 40~120℃ 15K Liquid crystal projector・power equipment・printed circuit board
US-828 828 Body 24×8×7.5 Microminiature ceramic φ2 Silver 16A AC250V 10A 180~290℃ Copy、Printer、Laser MFP
  • Select by Holder Models(US-60・62)
  • Select by Specifictions table
  • Select by CMJ table

What’s thermostatサーモスタットとは?

A device that stabilizes heat and temperature
The etymology for thermostat is a compound word combining “thermo” which means temperature or heat, and “stat” which means a stationary state. “Thermo” is how the word is pronounced in English, but in German it is pronounced “terumo” or “tamu”.
(1) Temperature regulator (controller): Maintains a certain degree of temperature.
(2) Excess temperature rise protector (limiter/protector): Turns off the heat source when    the temperature rises above a particular level.
(3) Temperature detector: Signals when the set temperature has been reached and causes  another operation to occur.
These are the main purposes of the thermostat.
Asahi’s Thermostat is a bimetal thermostat.
The temperature switch senses the temperature through the bimetal and controls the electricity contacts (turning them on or off).
There are various kinds of devices for temperature control and measurement.
on the image
Parts structure of the thermostat  Structure and principle of operation of the thermostat
622部品構成 Operation
No Technical data
1 The current capacity by
the load and voltage
2 Inrush current of the load
3 Electrical rating
of gold crossbar
contact products
4 Time constant of the thermostat
(Thermal response speed)

Contact us

Please inquire about products. Could you give us any suggestion about our web site?

Overseas Sales Offices Phone Fax e-mail
Overseas Affairs Section(TOKYO) +81(3)5843-0456 +81(3)3455-4052 thermostat-overseas@asahikeiki.co.jp
ASAHI KEIKI (HONG KONG) LIMITED +852-2730-3007 +852-2730-1107 representative@asahikeiki.imsbiz.com.hk
Domestic Sales Offices Phone Fax e-mail
Tokyo Office +81(3)5843-0452 +81(3)3455-4052 thermostat-sales@asahikeiki.co.jp
Nagoya Office +81(52)932-0651 +81(52)932-0653 thermostat-nagoya@asahikeiki.co.jp
Osaka Office +81(6)6310-8562 +81(6)6310-8500 thermostat-osaka@asahikeiki.co.jp
Sales Agent Phone Fax e-mail
Taga Hi-tech Co.,Ltd. +81(45)834-4078 +81(45)434-0598 sales@tagahitech.com
Ishihara Sangyo Co.,Ltd. +81(72)960-1011 +81(72)960-1021 isg@ishihara-ind.co.jp
Tokyo Office
3F, Dai-ni Takatori Bldg., 3-31, Shibaura 2-chome, Minato-ku, Tokyo 108-0023, JAPAN
General Affairs Dept.
Phone: +81 (3) 5843-0441 Fax: +81 (3) 5843-0450          Google マップ で表示するmap