engineering data sheet td-1412 repeat cycle-timer 1pst application note: 101 features l small size and weight l high-reliability design l hermetically sealed l high transient immunity l qualified to mil-prf-83726/22 l reverse polarity protection principle technical characteristics seal:hermetic tested per mil- std-883, method 1014 condition b, c 1x10 -8 atm, cm 3 /s max leakage finish: per mil-t-10727 tin plate terminals: "a" (tin plate) "w" (tin plate) solder-lug plug-in pcb mountable weight 0.5 ounce max. description the td-1412 time delay relays are designed with thick film hybrid microelectronics timing circuits and are packaged in a hermetically sealed military style enclosure. the td-1412 series are qualified to mil-prf- 83726/22 and designed to withstand severe environmental conditions encountered in military/aerospace applications. these relays are suited for use in power control, communication circuits and many other applications where power switching and high reliability are required over a wide temperature range. featuring leach ? power and control solutions www.esterline.com americas 6900 orangethorpe ave. p.o. box 5032 buena park, ca 90622 . . tel: (01) 714-736-7599 fax: (01) 714-670-1145 europe 2 rue goethe 57430 sarralbe france . . tel: (33) 3 87 97 31 01 fax: (33) 3 87 97 96 86 asia units 602-603 6/f lakeside 1 no.8 science park west avenue phase two, hong kong science park pak shek kok, tai po, n.t. hong kong tel: (852) 2 191 3830 fax: (852) 2 389 5803 data sheets are for initial product selection and comparison. contact esterline power systems prior to choosing a component. date of issue: 07/10 - 89 - page 1 of 3
electrical specification td-1412 input (control) parameters timing: a. operation, (flasher) b. method c. range d. accuracy repeat cycle timer fixed cycle 1 to 600 cycles/min. [5] 10% [1] recycle time 10 ms, max [4] operations: (x1-x2) a. input & control voltage b. operating current 18-32 vdc 5 ma, max @ +25 c transients: mil-std-704a, limit 1 a. spike susceptibility b. self-generated spikes +80 volts max -600 volts max none electromagnetic interference per mil-std-461a class 1d [2] duty rating continuous output (load) parameters contact form contact rating: voltage drop spst 250 ma, max. 2 vdc, max. dielectric strength: a. @ sea level, 60 hz b. @ 80,000 ft., 60 hz 1000 vrms [3] 350 vrms insulation resistance @ 500 vdc 1000 m w [3] general characteristics ambient temperatures range: a. operating b. non-operating -55 to +125 c -55 to +125 c vibration: a. sinusoidal 10-80 hz 80-3000 hz 0.06" da 30 g b. random: 50-2000 hz, mil-std-810 0.4 g 2 /hz shock, 0.5 ms, 1/2 sine, 3 axis 1,100 g acceleration, in any axis 100 g life at rated resistive load; minimum 1,000,000 operations numbering system pcb mount flange mount td-1412 - 2500 w td-1412 - 2500 a | | | | | | 1 3 4 1 3 4 m83726/22 - 2500 w m83726/22 - 2500 a | | | | | | | | 1 2 3 4 1 2 3 4 1. model number or basic "mil-prf" series number. 2. military "slash" number. 3. timing cycle, fixed: 100 milliseconds to 60 seconds. (see note 5). 4. mounting style and quality level (see note 6). w = printed circuit mountable. a = flange mount with solder hook terminals. date of issue: 0710 - 90 - page 2 of 3
mechanical specifications td-1412 notes [1] the accuracy specification applies for any combination of operating temperature and voltage. [2] emi test limits will not be exceeded during the timing interval or when continuously energized under steady state conditions, per paragraph 3.23, mil-prf-83726c. [3] terminals x1 and x2 must be connected together during the test. dielectric withstanding voltage and insulation resistance are measured at sea level between all mutually insulated terminals and between all terminals and case. [4] recycle time is defined as the maximum time power must be removed from terminal x1 to assure that a new cycle can be completed within the specified timing tolerance. [5] a four digit number defines the length of one complete cycle, expressed in milliseconds. "on" time is 50% of each cycle. the first three digits are significant figures, used to define the the specific cycle. the fourth digit represents the number of zeros to follow the first three digits. examples: - 1001 = 1 cycle/second (1,000 milliseconds cycle) - 2500 = 4 cycle/seconds (25 milliseconds cycle) - 6002 = 1 cycle/minute (60,000 milliseconds cycle) [6] quality level as specified in mil-r-83726b, paragraph 3.1.1, 3.1.2 and 3.1.3. date of issue: 07/10 - 91 - page 3 of 3
application notes n101 derating of contacts for dc voltages above nominal rating to establish a standard for the derating of relay contacts is, at best, a subjective practice. limitations are governed by the type of relay, contact gap, maximum voltage capabilities of the relay contact system, and the contact material. the most common method is to derate the contacts by use of the power formula, using the known current and voltage. this method is valid only for resistive loads, and is an approximation only; keeping in mind the limitations mentioned above. power = ie (current x voltage) i 2 e 2 = 2/3 i 1 e 1 example: a designer is working with a 55 volt dc system and has a relay rated at 10 amps resistive at 28 volts dc. what is the maximum current that can be switched at 55 vdc. i 1 = 10 amperes e 1 = 28 vdc e 2 = 55 vdc i 2 = ? (current ratings at 55 vdc resistive) i 2 e 2 = 2 i 1 e 1 /3 i 2 = 2 i 1 e 1 /e 2 3 = 2 (10 x 28)/55 x 3 = 560/165 i 2 = 3.4 amperes at 55vdc in addition, the user should always be concerned about the following: 1. derating contacts that are rated for less than 10 amperes at nominal voltage. 2. derating contacts for use in system voltages above 130 volts dc date of issue: 6/00 - 14 - page 1 of 1
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