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Hoping someone can help me with this project i'm working on. The thermode is made of a molybdeum alloy that gets heated by high current. Resistance of the tool is 0.3ohms it needs around 1000watts at 6v to heat the thermode. Its stated that the tool needed a " Pulse Transformer" to heat the thermode. My question is can a regular coil and core transformer be used instead? And what are the advantages using a Pulse transformer vs a coil and core?? Current transformer i have is a Microwave transformer rewound for 120v - 6v 900VA

Thanks

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  • \$\begingroup\$ Correction on my part , the output is 1000 watt total @ 6volts. Will look into this more. Corrently the plan is just to control via a PID and SSR with a standard transformer. \$\endgroup\$ – Icemaja Oct 8 '18 at 7:59
  • \$\begingroup\$ Are we takling 120 V AC drive? What's the duration? \$\endgroup\$ – winny Oct 8 '18 at 11:57
  • \$\begingroup\$ It will be 120VAC max duration for the heating cycle is 40 seconds. \$\endgroup\$ – Icemaja Oct 8 '18 at 18:14
  • \$\begingroup\$ So, you need a conventional AC transformer and nothing else. \$\endgroup\$ – winny Oct 8 '18 at 18:24
  • \$\begingroup\$ Went a head and ordered a 120V -2V 1000VA pulse transformer. Thats for the help . \$\endgroup\$ – Icemaja Oct 9 '18 at 23:54
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It could be that their recommending Pulse, the manufacturer, for your transformer supplier all transformers are just coils and cores. It could be that they are saying that Pulse have designed a transformer to work specifically for this application. By using a reworked microwave transformer you could end up destroying the tool as microwave transformers work at low frequencies. What you probably need is a SMPS check this out:

https://www.pulseelectronics.com/application_support/switching_power_supply_devices/

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  • \$\begingroup\$ Thanks Jak , after following your lead and doing alittle more research i came across a Pulse Control Module. Seem like this might be a option due to the short duration for heating cycle. It take the PID out to the SSR and converts it to a time proportional output. Any thoughts if this approach could work ?Max cycle duration is 40seconds, max temp of the thermode is 300 degrees C omega.ca/pptst_eng/PCM5.html \$\endgroup\$ – Icemaja Oct 8 '18 at 18:25
  • \$\begingroup\$ I dont think that one would work. If you need 1000W at 6V you'll need about 167A. Are you sure it's 1000W? at 100W it only need 17As ... also what do you mean about :rewound for 120v - 6v 900VA", what is the 900VA? \$\endgroup\$ – Jack Oct 8 '18 at 22:52
  • \$\begingroup\$ So just to clarify .Transformer is 120VAC @7.5A Primary - Secondary 6VAC @ 150A .Original MOT was 120VAC@7.5A - 2000VAC@0.45A. Rewound meaning the secondary and shunt was removed and rewired to produce 6VAC @ 150A.Alittle undersized for the 1000watt required but it works. The current setup gets the thermode 200 degrees in around 20 secs uncontrolled Resistive heating thermode directly connected to 6V 150A output. Just waiting for my PID to come in to fully test the setup.Just looking for away to precisely control the temp . That why i think they used pulse heating vs regular on/off control. \$\endgroup\$ – Icemaja Oct 9 '18 at 0:29

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