Temperature regulator for a soldering iron

At work with chips of KMOP it is necessary to use a low-power low-voltage soldering iron with grounding. And for a task of temperature of a sting it is more convenient to feed it through an electronic regulator of capacity.

The circuit of a regulator of temperature is provided on drawing 1.

of the Fig. 1 - the Circuit of a regulator of capacity of a soldering iron.

This circuit (see fig. 1) allows to establish soldering iron temperature in a wide range of working temperatures. And unlike other similar regulators, in this circuit as a key element the powerful field transistor with the N-channel and the isolated lock is used. In comparison with bipolar transistors and trinistor of MOSFET has smaller resistance a drain source abroach. It increases key efficiency, reduces heating, and allows to use it in this device without an additional heat-conducting path.

action Principle
On a chip of DA1 waiting multivibrator is accurate, is long which impulses is set by face values of components of a vremyazadayushchy chain of R4R5C3. The key on the VT1 transistor opens at positive tension on its lock.

For reduction of hindrances to the household equipment created by a regulator, operation of the multivibrator is synchronized from a network of an alternating current. For this purpose through a divider of R2-R3 pulsing tension moves on a conclusion of 2 chips of DA1. The threshold of operation of the comparator is established by the R3 resistor. On a conclusion of 3 chips of DA1 there will be impulses with the doubled frequency of a power line (100Гц) and the duration depending on the current provision of a cursor of the R4 resistor.

About details
DA1 chip - it is possible as to replace the integrated timer Kr1006vi1 with foreign analog of LM555 or NE555.
VD1-VD4 diodes on the most admissible current not less 3А.
It is possible to replace the key BUZ11 transistor on КП540 or IRF540.

"Useful circuits" of I.P.Rustle