update circuit diagram

doc/circuit.txt

@@ -0,0 +1,41 @@
+$ 1 5.0E-6 10.20027730826997 50 5.0 50
+178 640 304 736 304 0 1 0.2 1.199999759802672E-7 0.05 1000000.0 0.02 20.0
+d 608 400 608 336 1 0.805904783
+w 640 352 640 400 0
+w 640 336 608 336 0
+w 640 304 608 304 0
+w 608 304 608 336 0
+w 608 304 608 256 0
+w 608 256 784 256 0
+r 736 320 736 448 0 4700.0
+r 784 256 784 384 0 4700.0
+w 736 288 928 288 0
+w 640 400 608 400 0
+f 544 448 608 448 0 1.5
+w 608 432 608 400 0
+w 608 400 464 400 0
+w 608 464 608 528 0
+w 608 528 560 528 0
+w 560 528 560 432 0
+w 560 432 464 432 0
+w 544 448 544 496 0
+r 544 496 464 496 0 100.0
+w 560 528 464 528 0
+w 608 528 736 528 0
+w 736 528 784 528 0
+162 736 448 736 528 1 2.1024259 1.0 0.0 0.0
+162 784 384 784 496 1 2.1024259 1.0 0.0 0.0
+w 784 528 992 528 0
+w 928 288 928 496 0
+w 928 496 992 496 0
+w 784 496 784 528 0
+x 807 446 892 450 0 16 Power LED
+x 797 497 892 501 0 16 Release LED
+x 620 453 682 457 0 16 2N7000
+x 532 374 594 378 0 16 1N4001
+x 1007 519 1118 523 0 16 Magnetic Lock
+x 336 419 451 423 0 16 Release Switch
+x 282 517 455 521 0 16 Release Signal (3-20V)
+g 608 528 608 544 0
+R 608 256 608 224 0 0 40.0 12.0 0.0 0.0 0.5
+x 639 279 737 283 0 16 D2n V23105